Portable electrochemical cell with temperature control and surface morphology independence

ABSTRACT

The invention comprises portable, rugged and relatively compact electrochemical cells. Each may be removably and nondestructively secured to one surface of a substrate of indefinite size. In-situ electrochemical measurements may be made on portions of existing structures such as ships, bridges, or buildings. An electrochemical cell is disclosed which comprises an analytical chamber which can be utilized with either on-board or external potentiostats. The electrochemical cell has a mounting means which permits the cell to be secured to substrates with irregular surface morphology and to horizontal, vertical or intermediately oriented surfaces. The electrochemical cell provides a means to control the temperature of the electrolyte and the substrate area of interest to permit more accuract and consistent elecrochemical measurements. Said probe is capable of performing electrochemical measurements such as a monitoring corrosion, effectiveness, or integrity of conductive and nonconductive coatings on bare and coated metallic or conductive substrates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application61/297,947, filed on Jan. 25, 2010. This application is also aContinuation-In-Part of U.S. patent application Ser. No. 13/522,524filed on Jan. 24, 2011 as International Patent ApplicationPCT/US2011/022286.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under N00178-07-D-4078DO EHP7 awarded by United States Navy. The government has certain rightsin the invention. Per 48 CFR 52.227-11(b) the Federal Government shallhave a nonexclusive, nontransferable, irrevocable, paid-up license.

SEQUENCE LISTING

Not Applicable

BACKGROUND OF THE INVENTION

The invention comprises six different but related types ofelectrochemical cell. The six electrochemical cells of the inventionshare several important common features.

In the first instance, they are all portable. That is, they can each beused in the field, e.g. outside the laboratory. They can be moved to anydesired location to make electrochemical measurements on a wide varietyof different sized and shaped substrates. Obviously, even though theelectrochemical cells of the invention are designed to be usable outsidethe laboratory, they will work just as well in the laboratory, ifdesired.

Secondly, each electrochemical cell has the ability to be removably andnondestructively secured to one surface of a substrate of indefinitesize. This feature derives from the attachment means used with eachelectrochemical cell of the invention. Removable and nondestructiveattachment is defined herein to mean that the electrochemical cells ofthe invention may be attached and then easily removed from the substratewith no damage at all to the electrochemical cell and with only minimaldamage to the substrate. For example, the substrate may require a smallamount of cleaning because of spilled electrolyte. In addition, certaintypes of electrochemical measurements may require any coating of thesubstrate to be removed prior to taking the measurements. Obviously,this coating would have to be replaced in order to return the substrateto its original condition.

The attachment means permits the cells to be used to makeelectrochemical measurements on substrates of widely varying sizes andshapes. Since the attachment means will secure the electrochemical cellsof the invention to substrates of widely varying sizes, in-situelectrochemical measurements may be made on portions of existingstructures which may be quite large—for example ships, bridges, orbuildings.

Prior art electrochemical cells typically are limited to makingmeasurements on relatively small sized substrates, capable of beinginserted into the cell interior. Some prior art cells have the abilityto make measurements on larger substrates but require access to an edgeof the substrate. Thus, most all of the prior art electrochemical cellsare severely limited as to the size of the substrates they can workwith.

Lastly, they are all relatively compact and rugged compared to existingelectrochemical cells. For example, glass is often used in theconstruction of the prior art electrochemical cells and, for obviousreasons, a glass electrochemical cell cannot fairly be characterized asbeing “rugged”. The electrochemical cells of the invention are madeprimarily of modern polymeric materials which are much more rugged thanglass.

The first and most basic electrochemical cell comprises an analyticalchamber which can be utilized with existing prior art potentiostats.This chamber has means to contain the necessary electrolyte and means tosecure a counter electrode and a reference electrode therein. Thechamber also has an adjustable attachment means to permit the chamber tobe removably and nondestructively attached to and then removed from thesurface of a substrate of indefinite size.

The second electrochemical cell is a compact, rugged self-containedportable probe comprising an electrochemical cell and potentiostat toperform electrochemical measurements. The probe of the invention isparticularly useful to monitor corrosion on bare and coated substrates.The probe of the invention is designed to work on metals and otherconductive substrates. It is also designed to determine theeffectiveness or integrity of conductive and nonconductive coatings onconductive substrates.

The third electrochemical cell is a modification of the second cellwhich retains the self-contained electronics component of the secondelectrochemical cell, but eliminates the fluidics handling portion ofthe second embodiment.

The fourth electrochemical cell is a modification of the first threecells which allows for more adjustment of the attachment means to permitthe cell to be secured to substrates with irregular surface morphology,e.g. substrates which are not planar or have an irregular surface.

The fifth electrochemical cell is a modification of the third cell whichretains the self-contained electronics component of the secondembodiment and eliminates the fluidics handling portion of the secondembodiment. In addition, the fifth electrochemical cell permits accuratetemperature control of the electrolyte and of the local substrate areawhere the electrochemical measurements are being made. This cell alsohas an attachments means which permits the cell to be secured tosubstrates with a somewhat irregular surface morphology.

The sixth electrochemical cell is a modification of the fifth cell whicheliminates the self-contained electronics component.

Corrosion is a wide-spread problem that affects nearly all industry andgovernment sectors. A recent report determined that the direct cost ofcorrosion in the United States to be 3.1% of the Gross Domestic product(GDP) [G. H. Koch, et al. “Corrosion Costs and Preventive Strategies inthe United States,” Report by CC Technologies Laboratories, Inc. toFederal Highway Administration (FHWA), Office of Infrastructure Researchand Development, Report FHWA-RD-01-156, September 2001]. Thiscorresponds to $300B annually or $1000 per person. This figure includesonly the direct costs (e.g., corrosion prevention, corrosion inspection,and replacement or refurbishment of corroded structures). The indirectcosts (e.g., lost productivity, taxes, and overhead) were conservativelyestimated to be equal to the direct costs.

Thus, there is a pressing need to determine or monitor thesusceptibility or rate of corrosion of critical structures andcomponents in the field. Because corrosion is an electrochemicalprocess, electrochemical measurements are the most effective means todetermine if a material is corroding, is susceptible to corrosion, or isprotected from corrosion. These measurements are generally acquired byplacing the material being studied (the working electrode) in a liquidelectrolyte along with reference and counter electrodes to form anelectrochemical cell and using a potentiostat (a controlled power supplywith a sensitive zero-resistance ammeter (ZRA) or other galvanometer) toapply a potential or voltage between the reference electrode and thematerial being studied and measuring the current induced between thematerial and the counter electrode. The potential can be constant orvarying and it and the current can be either DC or AC. The relationshipof the current to the potential or the impedance (potential divided bycurrent for ac measurements) allows one skilled in the art to determinewhether the material is corroding, susceptible to corrosion or protectedfrom corrosion and if a coating is protective or not. The potentiostatsare generally relatively large and heavy bench instruments that requirestandard electrical power. An example of a prior art potentiostat wouldbe the Gamry Reference 3000 potentiostat that is approximately20-cm×23-cm×30-cm and weighs approximately 6 kg.

In the procedure described above, the material or specimen must berelatively small with dimensions in inches or centimeters to allow thespecimen to be immersed in a beaker or other container filled with asuitable electrolyte. For larger specimens or structures that are toolarge to immerse completely in an electrolyte, electrochemicalmeasurements can sometimes be acquired if the desired area of thestructure is horizontal or nearly horizontal by placing a bottomlesscylinder (or similar construction) on the structure and sealing it tothe structure with an o-ring, gasket, sealant, or other means so thatthe structure becomes the bottom of the container. Other configurationsallow the material to be vertical and form the side of a horizontalcylinder with openings along the top of the cylinder to allow theelectrolyte and electrodes to be added. The container is then filledwith the appropriate electrolyte and counter and reference electrodesimmersed into the electrolyte. A potentiostat is connected to thestructures and the electrodes and the electrochemical measurementsacquired. Once the measurements are completed, the setup must bereversed with the counter and reference electrodes removed and stored,the electrolyte drained and stored or disposed of, the bottomlesscylinder removed, and the structure cleaned of any sealant. Examples ofthis type of apparatus include the Gamry Instruments PTC1 Paint TestCell, the Princeton Applied Research Tait Cell K0307, and the PrincetonApplied Research Flat Cell K0235. The PTC1 Paint Test Cell and the FlatCell K0235 require the specimen to be clamped to the open end of thecontainer and thus limit the size and configuration of specimens capableto be studied. The Tait Cell holds the specimen via threaded rods and abacking plate. It could be attached to a large structure provided thatholes were drilled into the structure—a practice that is rarely allowed.All require a separate (large) potentiostat to be connected to theelectrodes and specimen.

An analysis detected a number of documents of interest related to thesepatents and to the present invention. Table 1 identifies these patents.

TABLE 1 Pat. Title Inventor U.S. Pat. No. 7,265,559 Self-calibratingcorrosion measurement field device with improved Hladky, K. et al.signal measurement and excitation circuitry U.S. Pat. No. 7,245,132Intrinsically safe corrosion measurement and history logging fieldPoirier, D. M. et device al. U.S. Pat. No. 7,239,156 Configurablecorrosion measurement field device Hladky, K et al. U.S. Pat. No.7,180,309 Electronic system for multielectrode sensors andelectrochemical Yang, X. S. devices U.S. Pat. No. 7,148,706 Embeddablecorrosion rate meters for remote monitoring of Srinivasan, R. etstructures susceptible to corrosion al. U.S. Pat. No. 7,397,370Monitoring an environment using a RFID assembly Bratkovski, AUS20060144719 Quantitative, real time measurements of localizedcorrosion events Gill, R. P. et al U.S. Pat. No. 7,034,660 Sensordevices for structural health monitoring Watters, D. G. et al. U.S. Pat.No. 6,776,889 Corrosion monitoring Atherton, E. U.S. Pat. No. 6,683,463Sensor array for electrochemical corrosion monitoring Yang, L. et al.U.S. Pat. No. 6,611,151 Coating assessment system based onelectrochemical noise Ruedisueli, R. L. et al. U.S. Pat. No. 6,320,395Apparatus and method for electrochemical corrosion monitoring Bosch,R.-W et al. U.S. Pat. No. 6,294,074 Electrode design for corrosionmonitoring using electrochemical Lin, Y. P. J. et al,. noisemeasurements U.S. Pat. No. 6,280,603 Electrochemical noise technique forcorrosion Jovancicevic, V. US20050122121 Direct Resistance MeasurementCorrosion Probe Gilboe, D.

These patents involve a variety of different means to detect corrosionor the corrosivity of the environment, including fiber opticmeasurements, strain gauges, electrical resistance, electrochemicalnoise, current between two electrodes, and degradation of witnessmaterial. Some are valid only for metal surfaces; others only forpainted surfaces. None include a self-contained electrochemical cellthat directly measures electrochemical properties of the structure ofinterest, stores the results, and transfers them to a portable computeror similar device.

SUMMARY OF THE INVENTION

The first and most basic electrochemical cell comprises an analyticalchamber which can be utilized with existing prior art potentiostats.This chamber has means to contain the necessary electrolyte and means tosecure a counter electrode and a reference electrode therein. Thechamber also has an adjustable attachment means to permit the chamber tobe attached to and then removed from the surface of a substrate ofindefinite size. The attachment means allows for nondestructiveattachment and removal from a substrate and does not require access toan edge of the substrate to provide the necessary attachment. Thisfeature allows for in-situ electrochemical measurements on portions ofexisting structures which may be quite large—for example, ships, bridgesor buildings.

The second embodiment of the invention comprises a self-containedportable electrochemical cell and potentiostat probe which simplifiesthe steps of determining or monitoring the susceptibility or rate ofcorrosion of critical structures and components in the field. The probecomprises three components: 1) a miniature potentiostat; 2) aself-contained electrochemical cell; and 3) a means to firmly attach theapparatus to the structure.

The electrochemical cell comprises an electrolyte reservoir, ameasurement or analytical compartment that is sealed to the substrate ofinterest via an o-ring or similar sealing means, counter and referenceelectrodes located in the measurement or analytical compartment, a meansto make electrical contact to the structure, and the pump, valves andtubing necessary to transport the electrolyte from the reservoir to themeasurement or analytical compartment and the reverse.

The probe is suitable for large and small structures and can be attachednondestructively. Measurements can be acquired in the field or in thelaboratory.

The third embodiment of the invention is a modification of the secondembodiment which retains the miniature potentiostat but does away withthe fluid handling portions of the second embodiment electrochemicalcell.

The fourth embodiment of the invention is a modification of the firstembodiment which allows for more adjustment of the attachment means topermit the cell to be secured to substrates with irregular surfacemorphology, e.g. substrates which are not planar or have an irregularsurface.

The fifth embodiment of the invention is a modification of the thirdembodiment which retains the self-contained electronics component of thesecond embodiment and eliminates the fluidics handling portion of thesecond embodiment. In addition, the fifth electrochemical cell permitsaccurate temperature control of the electrolyte and of the localsubstrate area where the electrochemical measurements are being made.This cell also has an attachments means which permits the cell to besecured to substrates with a somewhat irregular surface morphology.

The sixth embodiment of the invention is a modification of the fifthembodiment which eliminates the self-contained electronics component andis designed to be used with an external potentiostat.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a generic prior art potentiostat.

FIG. 2 shows a prior art electrochemical cell which works with an edgeof a sample.

FIG. 3 shows a prior art electrochemical cell which can work with asubstrate of indefinite size.

FIG. 4 shows the most basic electrochemical cell of the invention.

FIG. 5 shows a modification of the electrochemical cell shown in FIG. 4.

FIG. 6 shows a further modification of the electrochemical cell shown inFIG. 4.

FIG. 7 shows a further modification of the electrochemical cell shown inFIG. 4.

FIG. 8 shows an-isometric view of the probe of the second embodiment ofthe invention.

FIG. 9 shows a side view of the probe.

FIG. 10 shows a cross-sectional view along A-A of FIG. 9.

FIG. 11 shows another side view of the probe.

FIG. 12 shows a cross-sectional view along B-B of FIG. 11.

FIG. 13 shows a closer view of area C of FIG. 12.

FIG. 14 shows a block diagram of the electronics component.

FIG. 15 shows a block diagram of the fluidics component.

FIG. 16 shows the third embodiment of the invention mounted to avertical substrate.

FIG. 17 shows an analytical chamber for use in a further embodiment ofthe invention shown in FIG. 16.

FIG. 18 shows an embodiment of the third modification of the inventionwith the analytical chamber of FIG. 17 in place.

FIG. 19 shows a modification of the analytical chamber shown in FIG. 17.

FIG. 20 shows an embodiment of the third modification of the inventionusing the analytical chamber of FIG. 19.

FIG. 21 shows an embodiment of the cell of FIG. 7 wherein the attachmentmeans for biasing the cell towards a substrate has a modification topermit attaching the cell to substrates with widely varying surfacemorphology, e.g. substrates which are not planar or have an irregularsurface

FIG. 22 shows a plan view of an embodiment of the invention utilizingtemperature control and a somewhat more flexible attachment means thanthe attachment means of the first three embodiments.

FIG. 23 shows a side view of the embodiment shown in FIG. 22.

FIG. 24 shows a bottom view of the test fluid housing with theanalytical chamber inserted therein.

FIG. 25 shows a cross section of the test fluid housing along sectionline A-A of FIG. 24.

FIG. 26 shows details of a coarse height adjustment for theelectrochemical cell of FIGS. 22 and 23.

FIG. 27 shows details of the structure for mounting the electrolyte tankshown in FIGS. 22 and 23 to the electrochemical cell.

FIG. 28 shows a modification of the embodiment of the cell of FIGS. 22and 23, which eliminates the self-contained miniature potentiostat.

DETAILED DESCRIPTION

It should be understood that the terms “voltage” and “potential” areused interchangeably herein and mean the same thing.

FIG. 1 shows a block diagram of a generic prior art potentiostat 10comprising of a voltage/current generator 11; a electrometer 12 tomeasure the current induced by applied voltage or to measure the voltageinduced by applied current; a means 13 to make electrical connection tothe specimen being measured; a means 14 to make electrical connection toreference and counter electrodes immersed into an electrolyte along withthe specimen; a means 15 to convert the measurement into anelectrochemical impedance measurement; and a means for input/output 16.

FIG. 2 shows a prior art electrochemical cell that is designed to grip asample specimen at an edge thereof. Most prior art electrochemical cellsare designed to make electrochemical measurements on small size samplesor on samples which allow for the cell to be secured to one edgethereof.

In the first situation, the substrate of interest has to be small enoughto fit within the electrochemical cell. If the substrate of interest isnot small enough to fit within the electrochemical cell, the substratewould have to be partially destroyed by physically removing a suitablysized sample coupon. This sample coupon is then inserted into the cellin order to make the desired measurements.

In the second situation, the substrate of interest has to be smallenough to be inserted into the sample slot in the electrochemical cellor the substrate of interest must have an edge of a limited size andorientation on which the cell can be fastened in order to make thedesired electrochemical measurements.

FIG. 2 illustrates this latter type of prior art device. This figurecorresponds to a commercially available electrochemical cell known asPrinceton Applied Research Flat Cell Model K0235. Cell 70 comprises aglass cylinder 72 with ports 74 and 76 therein for receiving a counterelectrode and a reference electrode (not shown). The cell is closed atone end by a plate 78 and at the other end by fixture 80. Fixture 80 hasa slot 82 to permit a portion of sample 92 to be inserted therein. Screw88 is threaded into wall 86 of fixture 80 to bias the sample 92 againstwall 84 of fixture 80. Wall 84 of fixture 80 has an electrolyte opening90 therein to permit electrolyte contained in cylinder 72 to contact thesurface of sample 92. Plate 78 and fixture 80 are secured at each end ofcylinder 72 by threaded rods 94 which are secured to plate 78 andfixture 80 by nuts 96.

In practice some sort of sealing means [not shown] would normally beprovided around electrolyte opening 90 to seal opening 90 against thesurface of sample 92. This might take the form of an O-ring, gasket orother suitable device. Electrolyte is then poured into the cylinder 72to a suitable level and a reference electrode and a counter electrodeare mounted in ports 74 and 76 and suspended in the electrolyte withincylinder 72. A known prior art potentiostat is connected to the workingelectrode [sample 92] and the reference and counter electrodes and anydesired electrochemical measurements may be made.

Cell 70 is normally limited to handling samples of a limited size suchthat they can fit into the slot 82 in fixture 80 and such that they canbe supported by cell 70. If it is desired to fasten cell 70 to a largersample, the orientation and size of the portion of the sample which mustenter slot 82 becomes extremely important. This portion has to begenerally vertical and sized and oriented such that cell 70 can befastened thereto. Since ports 74 and 76 are not normally sealed, cell 70is clearly designed to function only in a generally horizontalorientation.

In certain instances it is known in the prior art to adhere acylindrical electrochemical cell to a generally horizontal substrate ofinterest. The cell may comprise a section of non-metallic tubing whichis open at the top and wherein the bottom end of the tubing is fastenedto the substrate with adhesive. The substrate of interest thus becomesthe bottom wall of the cell. There is no intent with this type of devicethat the cell be easily removable and repositionable. The adhesive usedis quite strong and would require serious force to be applied forremoval. The forces involved usually cause damage to the tubing and tothe substrate.

FIG. 3 illustrates this type of prior art device. Open cylinder 100 isadhered to substrate 102 by adhesive 104. Cylinder 100 may be made fromany suitable non-metallic material, such as glass, PVC or other suitableplastic. Electrolyte is then poured into the cylinder 100 to a suitablelevel and a reference electrode [not shown] and a counter electrode [notshown] are suspended within the electrolyte. A known prior artpotentiostat is connected to the working electrode [substrate 102] andthe reference and counter electrodes and any desired electrochemicalmeasurements may be made.

In contrast to the prior art devices, the electrochemical cell of thepresent invention even in its most basic form does not required damageto be done to the cell or to the substrate in order to take the desiredelectrochemical measurements. A minor cleaning of the surface in thearea affected by the cell mounting means may be required. This wouldcomprise removal of any contaminants or loose material which couldadversely affect the mounting. Depending upon the type ofelectrochemical measurements being taken, any coating material in theimmediate vicinity of the testing area might have to be removed tosecure access to the underlying metal, but this may not be necessary ifthe cell is used to make electrochemical measurements on the coating ofthe substrate.

In addition, the mounting means of the present invention permitselectrochemical measurements to be made on substrates of indefinitesize, such as ships, planes, bridges or buildings. The surfaces to bemeasured do not have to be strictly planar and may, indeed, be somewhatcurved.

FIG. 4 shows an electrochemical cell 108 comprising a cylinder 110 whichis open at the top end and has sealing means 112 attached to the bottomend. This may take the form of an O-ring, gasket or any other suitablesealing means. Ports 114 and 116 are provided for insertion of areference electrode and a counter electrode (not shown). These ports aredesigned such that the port with an electrode inserted therein would beliquid tight. This could be accomplished, for example, by the use of aplug which held the electrode therein. The plug could be secured andsealed within port 114 and/or 116 using an O-ring, gasket, screw threadsor any other suitable means.

At least one mounting means 118 is provided to removably andnondestructively secure call 108 to a surface of substrate 102. In thisfigure mounting means 118 and an identical mounting means 118′ areshown. Mounting means 118, 118′ provide for adjustment of the cell 108towards and away from substrate 102. This allows for the bottom end ofcylinder 110 to be biased against substrate 102 and permits sealingmeans 112 to seal cell 108 against substrate 102. Mounting means 118,118′ have a generally horizontal attachment arm 120, 120′ which securesthe mounting means to cylinder 110. In addition mounting means 118, 118′have a generally vertical leg 122, 122′ to hold securing means 124,124′. As shown, leg 122, 122′ can move vertically on arm 120, 120′.Securing means 124, 124′ may comprise a suction cup, a magnet,releasable adhesive means or any other device capable of releasably andnondestructively securing cell 108 to one surface of substrate 102.Certain applications may be such that only one mounting means 118 isnecessary, however two mounting means 118 will be necessary in manyapplications and three mounting means 118 is considered the optimalnumber for general usage, although more may be provided as the situationrequires. Each mounting means is independently adjustable in thevertical direction. This permits the cell 108 to be used on non-planarsurfaces.

Operation:

In operation, substrate 102 would be cleaned as necessary for thedesired measurements. This would involve cleaning in the area wheresecuring means 124, 124′ would contact substrate 102. In addition, thearea of substrate which would be directly under the footprint ofcylinder 110 would be cleaned and any coating in this area may have tobe removed in order to make the desired electrochemical measurements.Cell 108 would be then be secured to substrate 102 using mounting means118, 118′. The mounting means would be adjusted to bias cell 108 againstthe surface of substrate 102 to seal cell 108 to substrate 102 bycompressing sealing means 112. A suitable reference electrode andsuitable counter electrode would be secured in ports 114 and 116. Thecell would be filled with a suitable electrolyte. A conventional priorart potentiostat (not shown) would be electrically connected to thereference electrode and the counter electrode. In addition, thepotentiostat would be electrically connected to the working electrode(substrate 102) and the desired electrochemical measurements taken. Whenthe necessary electrochemical measurements are completed, the cell isemptied of electrolyte and sealing means 124, 124′ are removed fromsubstrate 102. The potentiostat would be disconnected from the cell andthe reference and counter electrodes removed and stored for further use.Any spilled electrolyte would be cleaned up and the substrate 102 wouldbe returned to its original condition. This might involve mild cleaningin the area of securing means 124, 124′ if a releasable adhesive is usedin securing means 124, 124′ or an even more minimal cleaning if securingmeans 124, 124′ involve the use of suction cups or magnets. The surfaceof substrate 102 in the area of the bottom opening of cylinder 110 mighthave to be recoated if a coating was removed to make the desiredmeasurements.

FIG. 5 shows a modification of the electrochemical cell of FIG. 4. Theelectrochemical cell 130 of FIG. 5 comprises a cylinder 132 which isopen at the top end and has a plate 138 closing its bottom end. Plate138 may be removably secured to the bottom of cylinder 132 or it mayoptionally be integral with cylinder 132. Plate 138 has an electrolyteopening 140 therein. This electrolyte opening 140 is provided with asealing means 142 surrounding electrolyte opening 140 at the exteriorsurface of plate 138 to seal cylinder 132 and plate 138 to the surfaceof substrate 102. Sealing means 142 may take the form of an O-ring,gasket or any other suitable means. Ports 134 and 136 are provided forinsertion of a reference electrode and a counter electrode (not shown).These ports are designed such that the port with an electrode insertedtherein would be liquid tight. This could be accomplished, for example,by the use of a plug which held the electrode therein. The plug could besecured and sealed within port 134 and/or 136 using an O-ring, gasket,screw threads or any other suitable means.

At least one mounting means 158 is provided to removably andnondestructively secure call 108 to a surface of substrate 102. In thisfigure two mounting means 158, 158′ are shown. Mounting means 158, 158′provide for adjustment of the cell 130 towards and away from substrate102. This allows for the electrolyte opening 140 in plate 138 to bebiased against substrate 102 and permits sealing means 142 to seal cell130 against substrate 102.

Mounting means 158, 158′ has a generally horizontal attachment arm 160,160′ which secures the mounting means to cylinder 132. In additionmounting means 158, 158′ has a generally vertical leg 162, 162′ to mountsecuring means 164, 164′ to the mounting means. As shown, leg 162, 162′can move vertically on arm 160, 160′. Securing means 164, 164′ maycomprise a suction cup, a magnet, releasable adhesive means or any otherdevice capable of releasably and nondestructively securing cell 108 toone surface of substrate 102.

Certain applications may be such that only one mounting means 158 isnecessary, however two mounting means 158, 158′ are considered necessaryin most applications and three mounting means are considered the optimalnumber for general usage although more may be provided as desired. Eachmounting means is independently adjustable in the vertical direction.This permits the cell 130 to be used on non-planar surfaces.

In operation, substrate 102 would be cleaned as necessary for thedesired measurements. This would involve cleaning in the area wheresecuring means 164, 164′ would contact the surface of substrate 102. Inaddition, the area of substrate 102 which would be directly under thefootprint of electrolyte opening 140 would be cleaned and any coating inthis area may have to be removed in order to make the desiredelectrochemical measurements. Cell 130 would be then be secured to thesurface of substrate 102 using mounting means 158, 158′. The mountingmeans would be adjusted to bias cell 130 against surface 102 to sealcell 130 to substrate 102 using sealing means 142. A suitable referenceelectrode and a suitable counter electrode (not shown) would be securedin ports 134 and 136. The cell would be filled with a suitableelectrolyte. A conventional prior art potentiostat (not shown) would beelectrically connected to the reference electrode and the counterelectrode. In addition, the potentiostat would be electrically connectedto the working electrode (substrate 102) and the desired electrochemicalmeasurements taken.

When the desired electrochemical measurements have been collected, theelectrolyte would be removed from cell 130, the potentiostatdisconnected, and the reference and counter electrodes removed fromports 134 and 136. The cell 130 would then be removed from substrate 102and any necessary cleaning of substrate 102 performed. Since the area ofthe electrolyte opening 140 is substantially less than the entirecross-section of cylinder 132, replacement of any coating of substrate102 would be simpler than when using the electrochemical cell of FIG. 4.

FIG. 6 shows an electrochemical cell which is a further modification ofthe electrochemical cell shown in FIG. 4. The electrochemical cell 130of FIG. 6 comprises a cylinder 172 which is closed at the top end byplate 174 and has a plate 178 closing its bottom end. Plates 174 and 178may be removably secured to the cylinder 172 or they may optionally beintegral with cylinder 172. Plate 178 has an electrolyte opening 180therein. This electrolyte opening 180 is provided with a sealing means182 surrounding electrolyte opening 180 at the exterior surface of plate178 to seal cylinder 172 and plate 178 to the surface of substrate 102.Sealing means 182 may take the form of an O-ring, gasket or any othersuitable means.

Ports 174 and 176 are provided for insertion of a reference electrodeand a counter electrode (not shown). These ports are designed such thatthe port with an electrode inserted therein would be liquid tight. Thiscould be accomplished, for example, by the use of a plug which held theelectrode therein. The plug could be secured and sealed within port 174and/or 176 using an O-ring, gasket, screw threads or any other suitablemeans.

Plate 174 has a filling/drain port 208 incorporated therein to permitthe cell 170 to be filled with electrolyte. This filling/drain meansincorporates a valve 210 to open and/or close port 208. This will permitthe cell 170 to be conveniently emptied of electrolyte when the desiredmeasurements have been taken as will be discussed below in the operationsection.

At least one mounting means 198 is provided to removably andnondestructively secure cell 170 to a surface of substrate 102. In thisfigure two mounting means 198, 198′ are shown. Mounting means 198, 198′provide for adjustment of the cell 170 towards and away from substrate102. This allows for the electrolyte opening 180 in plate 178 to bebiased against substrate 102 and permits sealing means 182 to seal cell170 against substrate 102.

Mounting means 198, 198′ have a generally horizontal attachment arm 200,200′ which secures the mounting means to cylinder 172. In additionmounting means 198, 198′ has a generally vertical leg 202, 202′ to mountsecuring means 204, 204′ to the mounting means. As shown, leg 202, 202′can move vertically on arm 200, 200′. Securing means 204, 204′ maycomprise a suction cup, a magnet, releasable adhesive means or any otherdevice capable of releasably and nondestructively securing cell 170 toone surface of substrate 102.

Certain applications may be such that only one mounting means 198 isnecessary, however two mounting means 198, 198′ are considered necessaryin most applications and three mounting means are considered the optimalnumber for general usage although more may be provided as desired. Eachmounting means is independently adjustable in the vertical direction.This permits the cell 170 to be used on non-planar surfaces.

Operation:

In operation, substrate 102 would be cleaned as necessary for thedesired measurements. This would involve cleaning in the area wheresecuring means 204, 204′ would contact the surface of substrate 102. Inaddition, the area of substrate 102 which would be directly under thefootprint of electrolyte opening 180 would be cleaned and any coating inthis area may have to be removed in order to make the desiredelectrochemical measurements. Cell 170 would be then be secured to thesurface of substrate 102 using mounting means 198, 198′. The mountingmeans would be adjusted to bias cell 170 against surface 102 to sealcell 170 to substrate 102 using sealing means 182. A suitable referenceelectrode and a suitable counter electrode (not shown) would be securedin ports 174 and 176. The cell would be filled with a suitableelectrolyte using filling/draining port 208. A conventional prior artpotentiostat (not shown) would be electrically connected to thereference electrode and the counter electrode. In addition, thepotentiostat would be electrically connected to the working electrode(substrate 102) and the desired electrochemical measurements taken.

When the desired electrochemical measurements have been collected, theelectrolyte can be removed from cell 170 by closing valve means 210 andthen quickly removing cell 170 from substrate 102 and then inverting thecell 170. A small amount of electrolyte would be spilled during thisprocedure, but most all of the electrolyte will be secured inside cell170. Then valve means 210 may be used to drain the used electrolytewhere and when desired. The potentiostat (not shown) can bedisconnected, and the reference and counter electrodes removed fromports 174 and 176. At this time any necessary cleaning of substrate 102performed. Since the area of the electrolyte opening 180 issubstantially less than the entire cross-section of cylinder 172,replacement of any coating of substrate 102 would be simpler than whenusing the electrochemical cell of FIG. 4.

FIG. 7 shows a further modification of the electrochemical cell shown inFIG. 4. The electrochemical cell 270 of FIG. 7 comprises a cylinder 272which is closed at the top end by plate 273 and has a necked-downportion 286 closing its bottom end. Plates 273 and necked-down portion286 may be removably secured to the cylinder 272 or they may optionallybe integral with cylinder 272. Necked-down portion 286 has anelectrolyte opening 280 therein. This electrolyte opening 280 isprovided with a sealing means 282 surrounding electrolyte opening 280 atthe exterior surface of necked-down portion 286 to seal cell 270 to thesurface of substrate 102. Sealing means 282 may take the form of anO-ring, gasket or any other suitable means.

Ports 274 and 276 are provided for insertion of a reference electrode(not shown) and a counter electrode (not shown). These ports aredesigned such that the port with an electrode inserted therein would beliquid tight. This could be accomplished, for example, by the use of aplug which held the electrode therein. The plug could be secured andsealed within port 274 and/or 276 using an O-ring, gasket, screw threadsor any other suitable means.

Plate 273 has a filling/drain port 308 incorporated therein to permitthe cell 270 to be filled with electrolyte. This filling/drain meansincorporates a valve 310 to open and/or close port 308. This will permitthe cell 270 to be conveniently emptied of electrolyte when the desiredmeasurements have been taken as will be discussed below in the operationsection.

Necked-down portion 286 is provided with a valve 284 near electrolyteopening 280. This permits the electrolyte opening 280 to be opened orclosed. Valve 284 may be a rotary valve, a slide valve or any othersuitable type of valve.

At least one mounting means 298 is provided to removably andnondestructively secure cell 270 to a surface of substrate 102. In thisfigure two mounting means 298, 298′ are shown. Mounting means 298, 298′provide for adjustment of the cell 270 towards and away from substrate102. This allows for the electrolyte opening 280 in necked-down portion286 to be biased against substrate 102 and permits sealing means 282 toseal cell 270 against substrate 102.

Mounting means 298 and 298′ have a generally horizontal attachment arm300, 300′ which secures the mounting means to cylinder 272. In additionmounting means 298, 298′ has a generally vertical leg 302, 302′ to mountsecuring means 304, 304′ to the mounting means. As shown, legs 302 and302′ can move vertically on arms 300, 300′. Securing means 304, 304′ maycomprise a suction cup, a magnet, releasable adhesive means or any otherdevice capable of releasably and nondestructively securing cell 270 toone surface of substrate 102.

Certain applications may be such that only one mounting means 298 isnecessary, however two mounting means 298, 298′ are considered necessaryin most applications and three mounting means are considered the optimalnumber for general usage although more may be provided if desired ornecessary. Each mounting means is independently adjustable in thevertical direction. This permits the cell 270 to be used on non-planarsurfaces.

Operation:

In operation, substrate 102 would be cleaned as necessary for thedesired measurements. This would involve cleaning in the area wheresecuring means 304, 304′ would contact the surface of substrate 102. Inaddition, the area of substrate 102 which would be directly under thefootprint of electrolyte opening 280 would be cleaned and any coating inthis area may have to be removed in order to make the desiredelectrochemical measurements. Cell 270 would be then be secured to thesurface of substrate 102 using mounting means 298, 298′. The mountingmeans would be adjusted to bias cell 270 against surface 102 to sealcell 270 to substrate 102 using sealing means 282. A suitable referenceelectrode (not shown) and a suitable counter electrode (not shown) wouldbe secured in ports 274 and 276. The cell would be filled with asuitable electrolyte using filling/draining port 308. During the fillingprocess, valve 284 would be closed. A conventional prior artpotentiostat (not shown) would be electrically connected to thereference electrode and the counter electrode. In addition, thepotentiostat would be electrically connected to the working electrode(substrate 102). At this time valve 284 would be opened to permitelectrolyte from the interior of the cell 270 to access the workingelectrode (substrate 102). The desired electrochemical measurements maythen be taken.

When the desired electrochemical measurements have been collected, thecell 270 may be removed from substrate 102 after closing valve means 310and 284. Securing means 304, 304′ would be removed from substrate 102and the cell 270 lifted off substrate 102. A small amount of electrolytemight be spilled on the surface of substrate 102 in the removal process,but most all of the electrolyte will be secured inside cell 270. Thesmall amount spilled can be easily cleaned up. Once cell 270 isseparated from substrate 102 and the potentiostat leads aredisconnected, electrolyte may be drained from cell 270 using valves 284and/or 310. Then the reference and counter electrodes (not shown) may beremoved from ports 274 and 276.

At this time any necessary cleaning of substrate 102 performed. Sincethe area of the electrolyte opening 280 is substantially less than theentire cross-section of cylinder 272 and since valves 284 and 310operate to secure most all of the electrolyte inside cell 270 duringremoval, clean-up of spilled electrolyte is minimal. At this time, anynecessary cleanup of the areas of substrate 102 under securing means304, 304′ can be performed and any coating of substrate 102 removedbecause of the electrochemical measurement process can be replaced inorder to restore substrate 102 to its original condition.

FIG. 8 shows an isometric view of the probe 20 of the second embodimentof the invention. The probe housing 21 is shown with the electronicscomponent housing 22 and the attachment mechanism 24. In this drawingthe attachment mechanism comprises suction cups, but it could also bemagnets, clamps, screws, bolts, or other means of attachment.

FIG. 9 shows another view of the probe 20. Electrical contact to a bare(uncoated) surface substrate is provided by springs 34. These springsprovide a means to apply a voltage or current to a substrate ofinterest. The springs also provide a means for making electricalmeasurements. For a coated substrate, electrical connection would beprovided by a separate lead (not shown). The port 31 allows thereference electrode 32 in FIG. 10 to be inserted into the probe andeasily replaced from the outside of the probe. An air/liquid separator38 allows the air to escape from the measurement chamber as it is beingflooded. The thumb screw 52 holds in place an optional removablecontainer filled with electrolyte.

The electronics component 50 (FIGS. 12 and 14) is contained in housing22. The interface connector 56 allows for connection to a computer orother device to enable programming the electronics component 50 and tooutput data. In addition, the probe could be powered with electricalenergy supplied via connector 56. The data transfer and programming canbe accomplished via connector 56 or by other means such as a wirelesstransmission.

FIG. 10 shows a cross-sectional view of the probe along line A-A of FIG.9. It shows the probe housing 21 with the attachment mechanism 24. Theanalytical chamber 30 is sealed to the substrate surface (not shown) byan o-ring 36. Electrical contact to a bare (uncoated) surface isprovided by springs 34. For a coated substrate, electrical connection iswould be provided by a separate lead (not shown). The referenceelectrode 32 and the counter electrode 33 are mounted in analyticalchamber 30. The electrolyte reservoir 44 holds the electrolyte until itis transferred to the analytical chamber 30 with the pumps and valves inthe fluidics compartment 40. The electrolyte reservoir 44 may be arefillable tank (not shown) which is integral with probe housing 21 or,more preferably, a removable container filled with electrolyte which canbe held in place by thumb screw 52.

Reference electrode 32 could be any of several commercially availablereference electrodes such as a saturated calomel electrode (SCE) or anyother electrode suitable for the type of electrochemical measurementdesired. In FIGS. 10 and 12, reference electrode 32 is illustrated as arod-type electrode. The counter electrode 33 is illustrated in FIGS. 3 band 4 b as a stainless steel mesh but it could take other forms such asa stainless steel or graphite rod or any other type of electrodesuitable for the measurement desired. The choice of a suitableelectrolyte would depend upon the exact type of measurement or testbeing performed. For example, in naval or marine corrosion tests, theelectrolyte might be a saline solution to simulate sea water.Alternatively the electrolyte might be an acidic solution, an alkalinesolution or a neutral solution depending upon the type of test beingperformed.

FIG. 11 shows a second view of the probe 20 showing the probe housing 21with the attachment mechanism 24. Control 42 allows adjustment of theprobe height to assure sealing to the substrate. Electrical contact to abare (uncoated) substrate is provided by springs 34. For a coatedsubstrate, electrical connection would be provided by a separate lead(not shown). Digital display 54 is mounted in electronics componenthousing 22.

FIG. 12 shows a cross-sectional view of the probe along line B-B of FIG.11 showing the probe housing 21 with the attachment mechanism 24. Theelectrolyte reservoir 44 holds the electrolyte until it is transferredto the analytical chamber 30 with the pumps and valves in the fluidicscompartment 40.

FIG. 13 shows a detail of area C of FIG. 12 showing one spring 34 ando-ring 36.

FIG. 14 shows a block diagram of the electronics component 50 comprisingpotentiostat 60, fluidics control 62, digital display 54, andinput/output means 66 all controlled by microprocessor 64. Input/outputmeans 66 enables programming instruction input and data output to anexternal computer or other device (not shown). An optional power supply68 may be part of electronics component 50 or power may be supplied froma source external to the probe 20. Input/output means 66 may alsoprovide for wireless transfer of information.

Potentiostat 60 can apply a potential between reference electrode 32 anda surface of a substrate. It can also apply a current between counterelectrode 33 and a surface of a substrate. Potentiostat 60 also has anelectrometer capable of measuring the potential between a surface of asubstrate and reference electrode 32 as a function of time or as afunction of applied current and also capable of measuring a currentbetween counter electrode 33 and a surface of a substrate as a functionof time or as a function of applied voltage. The applied potentialand/or current may be constant, they may vary (e.g. be ramped). Theapplied potential and/or current may be either AC or DC. When theapplied potential and/or current are AC, the frequency may be varied.

Microprocessor 64 preferably includes a clock to provide time stampinformation and storage means to store the collected data.

FIG. 15 shows a block diagram of the fluidics system including thereservoir tank 44, the pumps and valves system 40, the analyticalchamber 30 sealed with o-ring 36 to the material of interest 60. Alsoshown is the air separator and valve 38 to allow the air in theanalytical chamber 30 to be exhausted during the filling operation. Theair filter 46 allows air to be readmitted to the analytical chamber 30during the draining operation. Emergency vent 52 allows air to enter orleave the analytical chamber in case of an under or over pressure event.

Operation:

An operator or inspector will prepare the surface to be examined in amanner suitable for the measurement to be made. This preparation couldinclude a simple cleaning of the surface, light abrasion to expose afresh surface, heavy abrasion or grit blasting to remove material suchas a paint coating if the underlying metal is to be examined. Theoperator would mount the apparatus onto the surface using suction cups,magnets, or other attachment means. The operator would then program theunit to take whatever electrochemical measurements are desired. Thesemeasurements could include a potential sweep or hold with the currentbeing measured as a function of potential or of time, a current sweep orhold with the voltage being measured as a function of current or time,an oscillatory (ac) potential with the frequency being swept or heldwith the current being measured as a function of frequency, or the opencircuit potential and current being measured as a function of time. Theelectrolyte would be transferred from the reservoir to the analysischamber and the measurements being acquired either immediately or afteran appropriate hold time. After the measurements are completed, theelectrolyte would be transferred back to the reservoir and the unitremoved from the structure. Data could then be transferred to a portablecomputer or similar device for analysis.

FIG. 16 shows the third embodiment of the electrochemical cell of theinvention mounted to a generally vertical surface 103. The previouselectrochemical cells have all been illustrated as takingelectrochemical measurements on horizontal substrates. Theelectrochemical cell of this invention may be used to makeelectrochemical measurements on substrates which are not horizontal. Inparticular the closed cell embodiments as shown in FIGS. 6 and 7 aresuitable for making measurements on vertical substrates. Since themounting means will mount the cell to essentially any substrate,measurements can even be made on substrates which are inclined pastvertical. In addition, the previous embodiments were designed for usewith a conventional prior art potentiostat. It is possible to provide anelectronics package to the previous embodiments and give them thecapability to function without an external potentiostat. The embodimentshown in FIG. 16 is particularly suited for making such measurements.

The electrochemical cell 370 of FIG. 16 comprises a cylinder 372 whichis closed at one end by plate 373 and has a necked-down portion 386closing the other end. Plate 373 and necked-down portion 386 may beremovably secured to the cylinder 372 or they may optionally be integralwith cylinder 372. Necked-down portion 386 has an electrolyte opening380 therein. This electrolyte opening 380 is provided with a sealingmeans 382 surrounding electrolyte opening 380 at the exterior surface ofnecked-down portion 386 to seal cell 370 to the surface of a substrate103. Sealing means 382 may take the form of an O-ring, gasket,releasable adhesive or any other suitable means.

Ports 374 and 376 are provided for insertion of a reference electrode(not shown) and a counter electrode (not shown). These ports aredesigned such that the port with an electrode inserted therein would beliquid tight. This could be accomplished, for example, by the use of aplug which held the electrode therein. The plug could be secured andsealed within port 374 and/or 376 using an O-ring, gasket, screwthreads, releasable adhesive or any other suitable means.

A filling/drain port 408 is incorporated into a suitable portion ofcylinder 372 in order to permit the cell 370 to be filled withelectrolyte when cylinder 372 is disposed in a generally horizontalposition as it would be if cell 370 was secured to a generally verticalsubstrate 103. This filling/drain means incorporates a valve 410 to openand/or close port 408. A similar filling/drain port 408′ is provided ata suitable location on cylinder 372 generally opposite to filling/drainport 408. Filling/drain port 408′ has a valve 410′ which permitsfilling/drain port 408′ to be opened or closed. This provision of afilling/drain port 408′ will permit the cell 370 to be convenientlyemptied of electrolyte while cell 370 remains mounted to the generallyvertical substrate 103. This will be further discussed below in theoperation section.

An air-liquid separator 311 is provided in a portion of cylinder 372near port 408. This permits gasses (e.g. air) trapped inside cell 370 toescape while the cell 370 is being filled with electrolyte. Air-liquidseparator 311 does not have to be near the port 408. Other locationscould be used as desired. The air-liquid separator simply has to be insuitable position so as to permit gasses to be exhausted from cell 370as electrolyte is introduced therein. It is assumed, herein, that cell370 would usually be mounted to the generally vertical substrate priorto filling the cell with electrolyte although this is not absolutelynecessary.

Necked-down portion 386 is provided with a valve 384 near electrolyteopening 380. This permits the electrolyte opening 380 to be opened orclosed. Valve 384 may be a rotary valve, a slide valve or any othersuitable type of valve.

Housing 412 is secured to plate 373. This housing contains electronicscomponent 420 which comprises a miniature potentiostat and the necessarymeans to initiate, monitor and control the electrochemical measurementprocess. Electronic component 420 also has means therein to store theelectrochemical measurements when they are taken and means to outputsaid stored measurements when desired. This electronics component issimilar to electronics component 50 shown in FIGS. 12 and 14 anddescribed earlier. Jack 424 is provided in housing 412 to permit anelectrical connection from the electronics component 420 to a counterelectrode (not shown). Jack 426 is provided in housing 412 to enableelectrical connection between the electronic component 420 and theworking electrode (in this instance, generally vertical substrate 103).Jack 428 is provided to enable electrical connection between electronicscomponent 420 and a reference electrode (not shown).

At least one mounting means 398 is provided to removably andnondestructively secure cell 370 to a surface of generally verticalsubstrate 103. In this figure two such mounting means 398, 398′ areshown. Mounting means 398, 398′ provide for adjustment of the cell 370towards and away from generally vertical substrate 103. This allows forthe electrolyte opening 380 in necked-down portion 386 to be biasedagainst substrate 103 and permits sealing means 382 to seal cell 370against substrate 103.

Mounting means 398 and 398′ have an attachment arm 400, 400′ whichsecures the mounting means to cylinder 372. In addition mounting means398, 398′ have a leg 402, 402′ to mount securing means 404, 404′ to themounting means. As shown, legs 402 and 402′ can move along thelongitudinal axis of cylinder 372 across arms 400, 400′. Securing means404, 404′ may comprise suction cups, magnets, releasable adhesive meansor any other device capable of releasably and nondestructively securingcell 370 to one surface of generally vertical substrate 103.

It is possible that two mounting means 398, 398′ would be sufficient tomount cell 370 to generally vertical substrate 103 but it is more likelythat three such mounting means would be considered the optimal numberfor a vertical measurement. Obviously, more than three mounting meanscould be used, if desired. Each mounting means is independentlyadjustable along the longitudinal axis of cylinder 372 in order topermit the cell 370 to be used on non-planar surfaces.

Operation:

In operation, substrate 103 would be cleaned as necessary for thedesired measurements. This would involve cleaning in the area wheresecuring means 404, 404′ would contact the surface of substrate 103. Inaddition, the area of substrate 103 which would be directly under thefootprint of electrolyte opening 380 would be cleaned and any coating inthis area may have to be removed in order to make the desiredelectrochemical measurements.

Cell 370 would then be secured to the surface of generally verticalsubstrate 103 using mounting means 398, 398′. The mounting means wouldbe adjusted along the longitudinal axis of cylinder 372 to bias cell 370against surface 103 in order to seal cell 370 to substrate 103 usingsealing means 382. A suitable reference electrode (not shown) and asuitable counter electrode (not shown) would be secured in ports 374 and376.

Electrical connections between electronics component 420 and thereference and counter electrodes would be made using jacks 428 and 424.In addition, electronics component 420 would be electrically connectedto the working electrode (generally vertical substrate 103) using jack426. The cell would be filled with a suitable electrolyte usingfilling/draining port 408. During the filling process, valves 384 and410′ would be closed. When the cylinder 372 is filled with electrolyte,valve 384 would be opened to permit electrolyte from the interior of thecell 370 to access the working electrode (generally vertical substrate103). The desired electrochemical measurements may then be taken.

When the measurements have been collected, the cell 370 may be removedfrom generally vertical substrate 103 after making sure that valve means410, 410′ and 384 are closed. Securing means 404, 404′ would be removedfrom generally vertical substrate 103 and the cell 370 lifted off. Asmall amount of electrolyte might be spilled in the removal process, butmost all of the electrolyte will be secured inside cell 370. The smallamount spilled can be easily be cleaned up. Once cell 370 is separatedfrom generally vertical substrate 103 and the electronic component leadsare disconnected, electrolyte may be drained from cell 370 using valves234, 410 and 410′. Then the reference and counter electrodes (not shown)may be removed from ports 374 and 376.

At this time any necessary cleaning of generally vertical substrate 103may be performed. Since the area of the electrolyte opening 380 issubstantially less than the entire cross-section of cylinder 372 andsince valves 384, 410 and 410′ operate to secure most all of theelectrolyte inside cell 370 during removal, clean-up of spilledelectrolyte is minimal. At this time, any necessary clean up of theareas of generally vertical substrate 103 under securing means 404, 404′can be performed and any coating previously removed from the surface ofgenerally vertical substrate 103 prior to initiating the electrochemicalmeasurement process can be replaced in order to restore generallyvertical substrate 103 to its original condition.

FIG. 17 illustrates an analytical chamber 471 designed to be used withanother embodiment of the electrochemical cell of the inventionillustrated in FIG. 18.

The analytical chamber 471 of FIG. 17 comprises a cylinder 473 which isclosed at the top end by removable portion 475 and closed at the bottomby plate 477. Plate 477 may be removably secured to the cylinder 473(not shown) or it may be integral with cylinder 473 as shown. Removableportion 475 is removably secured to cylinder 473 by any suitable means.For example, an O-ring (not shown) could be used to removably secureportion 475 to cylinder 473 or screw threads could be used or any othersuitable means. An electrolyte opening 479 is provided in the bottomplate 477. A slide valve 485 is secured to the bottom portion of plate477 at the external side thereof. Slide valve 485 permits electrolyteopening 479 to be open or closed depending upon the position of slidevalve 485. Sealing means 487 is provided between electrolyte opening 479and slide valve 485 to prevent electrolyte leakage when slide valve 485is closed. Sealing means 487 may take the form of an O-ring, gasket,releasable adhesive or any other suitable means.

The analytical chamber 471 also has openings 481 and 483 in plate 477.These openings permit a reference electrode (not shown) and a counterelectrode (not shown) to penetrate to the interior of analytical chamber471 when the analytical chamber is inserted into the electrochemicalcell 490 shown in FIG. 18

A resealable elastomeric material 488, 488′ is placed inside openings481 and 483 to seal them. This material permits the electrodes topenetrate into the analytical chamber and then seals itself when theelectrodes are removed.

This resealable elastomeric material may be similar to the type ofmaterial used to seal multi-dose vials in the medical arts. These vialshold multiple doses of medicines which are intended to be injected intoa patient. The needle of a hypodermic syringe penetrates the elastomericmaterial permitting a single dose of the medicine to be withdrawn intothe hypodermic syringe and the needle is then withdrawn from the vial.As the needle leaves the elastomeric material, it seals itself.

It is also possible (although not shown in FIG. 17) to use a pressuresensitive adhesive tape to seal openings 481, 483. The tape could coverthe electrode openings at the inner or outer surface of plate 477 andthus seal them prior to use. When the reference and counter electrodespenetrate into openings 481 and 483, they will easily puncture thepressure sensitive tape and the cell would be ready to use.

FIG. 18 illustrates another embodiment of the electrochemical cell ofthe invention. Unlike the previous embodiments this embodiment has aremovable analytical chamber. It also has an electronics componentsimilar to the one shown at 50 in FIG. 11 and shown at 420 in FIG. 16.

The electrochemical cell 490 shown in FIG. 18 comprises a separateanalytical chamber 471 as shown in FIG. 17 and a base fixture 472.Analytical chamber 471 comprises a cylinder 473 which is closed at thetop end by removable portion 475 and closed at the bottom by bottomplate 477. Bottom plate 477 may be removably secured to the cylinder 473or it may be integral with cylinder 473 as shown. Removable portion 475is removable secured to cylinder 473 by any suitable means. For example,an O-ring (not shown) could be used to removably secure portion 475 tocylinder 473 or screw threads could be used or any other suitable means.An electrolyte opening 479 is provided in the bottom plate 477. A slidevalve 485 is secured to the bottom portion of plate 477 at the externalside thereof. Slide valve 485 permits electrolyte opening 479 to be openor closed depending upon the position of slide valve 485. Sealing means487 is provided between electrolyte opening 479 and slide valve 485 toprevent electrolyte leakage when slide valve 485 is closed. Sealingmeans 487 may take the form of an O-ring, gasket, releasable adhesive orany other suitable means.

The analytical chamber 471 also has openings 481 and 483 in bottom plate477. A resealable elastomeric material 488, 488′ is placed insideopenings 481 and 483 to seal them. This material permits the electrodesto penetrate into the analytical chamber and then seals itself when theelectrodes are removed. Openings 481 and 483 permit a referenceelectrode 505 and a counter electrode 507 to penetrate to the interiorof analytical chamber 471 when the analytical chamber is inserted intothe base fixture 472 shown in FIG. 18.

Base fixture 472 comprises a cylinder 492 closed at the top end by plate493 and closed at the bottom by plate 497. Plate 493 has a large openingtherein to receive the analytical chamber 471. Bottom plate 497 has anelectrolyte opening 498 therein designed to permit electrolyte from theanalytical chamber to flow onto the surface of substrate 102. Cylinder492 has a slot 495 on one side thereof which slot is designed to receiveslide valve 485 of analytical chamber 471. The slot extends from the topportion of cylinder 492 to the bottom thereof and extends thru plate493.

Cylinder 492 has a rod-like reference electrode 505 and a rod-likecounter electrode 507 mounted on bottom plate 497. The electrodes extendvertically upwards from bottom plate 497 and are longer than thethickness of bottom plate 477 of analytical chamber 471. The electrodesare positioned on bottom plate 477 so as to be capable of passingthrough openings 481 and 483 in the bottom of analytical chamber 471when the analytical chamber is inserted into base fixture 472.

Sealing means 499 is provided on the upper portion of plate 497 and sopositioned as to surround the electrolyte opening 479 of analyticalchamber 471 and the electrolyte opening 498 of bottom plate 497. Sealingmeans 499 is also in contact with the bottom of slide valve 485. Sealingmeans 499 helps to prevent the escape of electrolyte from analyticalchamber 471 during operation of electrochemical cell 490.

Sealing means 505 is provided at the external side of plate 487 andsurrounds electrolyte opening 498 therein. This permits the cell 490 tobe sealed to the surface of substrate 102 in operation. Sealing means487, 499 and 505 are shown as O-rings but they could easily be any othersuitable type of sealing means such as a gasket, etc., etc.

Housing 513 is fastened to cylinder 492 and contains electronicscomponent 520. As noted above, electronics component 520 is similar indesign and function to electronics component 50 in FIG. 12 andelectronics component 420 in FIG. 16. Electrical connections 509 and 511connect counter electrode 07 and reference electrode 505, respectively,to electronics component 520. Jack 515 is provided in housing 513 toelectrically connect electronics component 520 with the workingelectrode ((substrate 102).

Electrochemical cell 490 has a mounting means 500, 500′ for removablyand nondestructively securing the cell to substrate 102. Mounting means500, 500′ comprises a generally horizontal arm 501, 501′ which isfastened to cylinder 492. Generally vertical legs 502, 502′ ride on theends of arms 501, 501′ and carry securing means 504, 504′. Vertical legs502, 502′ ride up and down on arms 501, 501′ so as to permit cell 490 tobe biased against one surface of substrate 102. Securing means 504, 504′could be suction cups, magnets, plates with releasable adhesive thereonor any other type of securement means which would permit the cell 490 tobe removably and nondestructively secured to substrate 102.

Operation:

Separate analytical chamber 471 would be filled with a suitableelectrolyte before use of the cell 490. Analytical chamber 471 could beclosed by positioning slide valve 485 to close electrolyte opening 479.Elastomeric seal means 488 and 489 are provided inside openings 481 and483 to seal them prior to use. When the reference and counter electrodespenetrate into openings 481 and 483, they will easily puncture theelastomeric means 488, 489 and the cell would be ready to use.

Separate analytical chamber 471 could be assembled to base fixture 472prior to fastening the base fixture 472 to substrate 102 or it could beinserted after the base fixture 472 has been fastened to substrate 102.Once the base fixture 472 has been secured to the surface of substrate102 by securing means 500, 500′, and once analytical chamber 471 hasbeen inserted fully into base fixture 472, the necessary electricalconnection between electronics component 520 and the working electrode(substrate 102) may be made using jack 515. Slide valve 485 would beopened to permit electrolyte from the interior of analytical chamber 471to contact the working electrode (substrate 102) and the necessaryelectrochemical measurements could be made.

After the desired electrochemical measurements have been taken, slidevalve 485 would be closed and the cell 490 removed from the substrate102. The connection between the electronics component 520 and theworking electrode (substrate 102) would be removed and the analyticalchamber 471 would be removed from base fixture 472. A fresh analyticalchamber 471 could be inserted into base fixture 472 in order to makefurther electrochemical measurements, as desired.

It is noted that the connection to the working electrode (substrate 102)may be made using springs (not shown) fastened to the bottom of plate487 and electrically connected to electronics component 520. This wouldbe similar to the springs 34 shown in FIGS. 12 and 13.

FIG. 19 illustrates an analytical chamber designed to be used withanother embodiment of the electrochemical cell of the inventionillustrated in FIG. 20.

The analytical chamber 517 of FIG. 19 comprises a cylinder 512 which isclosed at the top end by top plate 519 and closed at the bottom end bybottom plate 522. Plates 519 and 522 may be removably secured to thecylinder 512 (not shown) or they may be integral with cylinder 512 asshown. An electrolyte opening 524 is provided in bottom plate 522. Arotating valve 530 is secured to chamber 517. Rotation of this valve 530opens or closes electrolyte opening 524 located in bottom plate 522.Rotating valve 530 comprises a rod 533 which penetrates top plate 519and is rotatable and secured in bottom plate 522. Plate 535 is securedto rod 533 and rotates with rod 533. Knob 537 is provided to permitrotating valve 530 to be rotated. Sealing means 523 is provided at thetop of electrolyte opening 524 to prevent electrolyte leakage whenrotating valve 530 is closed. Sealing means 525 is provided at theexternal side of electrolyte opening 524 to seal analytical chamber 517into the body of the electrochemical measurement means illustrated inFIG. 20. Sealing means 523 and 525 may take the form of an O-ring,gasket, releasable adhesive or any other suitable means.

The analytical chamber 517 also has openings 526 and 527 in bottom plate522. These openings permit a reference electrode (not shown) and acounter electrode (not shown) to penetrate to the interior of analyticalchamber 517 when the analytical chamber is inserted into theelectrochemical measurement means shown in FIG. 20

A small strip 528 of pressure sensitive adhesive tape is applied on theexterior side of bottom plate 522 to seal openings 526, 527. Optionally,the pressure sensitive adhesive tape could be applied on the innersurface of bottom plate 522 and thus seal openings 526, 527 prior touse. When the reference and counter electrodes penetrate into openings526 and 527, they will easily puncture the pressure sensitive adhesivetape and the cell would be ready to use.

An alternate to the strip 528 of pressure sensitive adhesive tape wouldbe to use a resealable elastomeric material inside openings 526 and 527to seal them. This would be very similar to what is shown in FIG. 17 anddescribed above. This material would permit the electrodes to penetrateinto the analytical chamber and then would seal itself when theelectrodes are removed.

This resealable elastomeric material may be similar to the type ofmaterial used to seal multi-dose vials in the medical arts. These vialshold multiple doses of medicines which are intended to be injected intoa patient. The needle of a hypodermic syringe penetrates the elastomericmaterial permitting a single dose of the medicine to be withdrawn intothe hypodermic syringe and the needle is then withdrawn from the vial.As the needle leaves the elastomeric material, it seals itself.

FIG. 20 illustrates another embodiment of the electrochemical cell ofthe invention similar to that shown in FIG. 18. This embodiment also hasa removable analytical chamber and an electronics component similar tothe one shown at 50 in FIG. 12 and shown at 420 in FIG. 16.

The electrochemical cell 590 shown in FIG. 20 comprises a separateanalytical chamber 517 as shown in FIG. 19 and a base fixture 518.Analytical chamber 517 comprises a cylinder 512 which is closed at thetop end by plate 519 and closed at the bottom by bottom plate 522.Bottom plate 522 may be removably secured to the cylinder 512 or it maybe integral with cylinder 512 as shown. An electrolyte opening 524 isprovided in the bottom plate 522. A rotating valve 530 runs from topplate 519 into the analytical chamber and is secured to the bottom plate522. Rotating valve 530 comprises a generally vertical rod 533, a bottomflap 535 and a knob 537. Knob 537 permits rod 533 to be rotated causingflap 535 to rotate over the top of electrolyte opening 524 closing theelectrolyte opening. This permits electrolyte opening 524 to be open orclosed depending upon the position of rotating valve 530. Sealing means523 is provided between electrolyte opening 524 and bottom flap 535 toprevent electrolyte leakage when rotating valve 535 is closed. Sealingmeans 523 may take the form of an O-ring, gasket, releasable adhesive orany other suitable means.

The analytical chamber 517 also has openings 526 and 527 in bottom plate522. A small strip 528 of pressure sensitive tape emplaced on theexterior side of bottom plate 522 covers openings 526, 527 and sealsthem. These openings permit a reference electrode 597 and a counterelectrode 596 to penetrate to the interior of analytical chamber 517when the analytical chamber is inserted into the base fixture 518. Whenthe electrodes begin to enter openings 526 and 527 they will easilypenetrate the strip 528 of pressure sensitive adhesive tape.

Base fixture 518 comprises a cylinder 592 closed at the top end by plate593 and closed at the bottom by plate 594. Plate 593 has a large openingtherein to receive the analytical chamber 517. Bottom plate 594 has anelectrolyte opening 529 therein designed to permit electrolyte from theanalytical chamber to flow onto the surface of substrate 102.

Cylinder 592 has a rod-like reference electrode 597 and a rod-likecounter electrode 596 mounted on bottom plate 522. The electrodes extendvertically upwards from bottom plate 522 and are longer than thethickness of bottom plate 522 of analytical chamber 517. The electrodesare positioned on bottom plate 522 so as to be capable of passingthrough openings 527 and 526 in the bottom of analytical chamber 517when the analytical chamber is inserted into base fixture 518.

Sealing means 525 is provided on the upper portion of plate 594 and sopositioned as to surround the electrolyte opening 524 of analyticalchamber 517 and the electrolyte opening 526 of bottom plate 594. Sealingmeans 525 helps to prevent the escape of electrolyte from analyticalchamber 517 during operation of electrochemical cell 590.

Sealing means 595 is provided at the external side of plate 594 andsurrounds electrolyte opening 529 therein. This permits the cell 590 tobe sealed to the surface of substrate 102 in operation. Sealing means523, 525 and 595 are shown as O-rings but they could easily be any othersuitable type of sealing means such as a gasket, releasable adhesive orany other suitable means.

Housing 621 is fastened to cylinder 592 and contains electronicscomponent 620. As noted above, electronics component 620 is similar indesign and function to electronics component 50 in FIG. 12, electronicscomponent 420 in FIG. 16 and electronics component 520 in FIG. 18Electrical connections 599 and 605 connect counter electrode 596 andreference electrode 597, respectively, to electronics component 620.Jack 622 is provided in housing 621 to electrically connect electronicscomponent 620 with the working electrode (substrate 102).

Electrochemical cell 590 has a mounting means 600, 600′ for removablyand nondestructively securing the cell to substrate 102. Mounting means600, 600′ comprises a generally horizontal arm 601, 601′ which isfastened to cylinder 592. Generally vertical legs 602, 602′ ride on theends of arms 601, 601′ and carry securing means 604, 604′. Vertical legs602, 602′ ride up and down on arms 601, 601′ so as to permit cell 590 tobe biased against one surface of substrate 102. Securing means 604, 604′could be suction cups, magnets, plates with releasable adhesive thereonor any other type of securement means which would permit the cell 590 tobe removably and nondestructively secured to substrate 102.

Operation:

Separate analytical chamber 517 would be filled with a suitableelectrolyte before use of the cell 590. Analytical chamber 517 would beclosed by using rotating valve 530 to close electrolyte opening 524. Thestrip 528 of pressure sensitive adhesive tape covers electrode openings526 and 527 and seals them prior to use. When the reference and counterelectrodes penetrate into openings 526 and 527, they will easilypuncture the strip 528 of pressure sensitive adhesive tape and the cellwould be ready to use.

Separate analytical chamber 517 could be assembled to base fixture 518prior to fastening the base fixture 518 to substrate 102 or it could beinserted after the base fixture 518 has been fastened to substrate 102.Once the base fixture 518 has been secured to the surface of substrate102 by securing means 600, 600′, and once analytical chamber 517 hasbeen inserted fully into base fixture 518, the necessary electricalconnection between electronics component 620 and the working electrode(substrate 102) may be made using jack 622. Rotating valve 530 would beopened to permit electrolyte from the interior of analytical chamber 517to contact the working electrode (substrate 102) and the necessaryelectrochemical measurements could be made.

After the desired electrochemical measurements have been taken, rotatingvalve 530 would be closed and the cell 590 removed from the substrate102. The connection between the electronics component 620 and theworking electrode (substrate 102) would be removed and the analyticalchamber 517 would be removed from base fixture 518. A fresh analyticalchamber 517 could be inserted into base fixture 518 in order to makefurther electrochemical measurements, as desired.

It is noted that the connection to the working electrode (substrate 102)may be made using springs (not shown) fastened to the bottom of plate594 and electrically connected to electronics component 620. This wouldbe similar to the springs 34 shown in FIGS. 12 and 13.

In the embodiment shown in FIG. 18 and FIG. 20 two mounting means areshown attached to the base fixture. In certain environments, onemounting means may be sufficient to properly secure electrochemical cell490 and 590 to the substrate. It is thought that most situations wouldrequire two mounting means. Obviously more than two such mounting meansmay be used. It is envisaged that three mounting means is the optimalnumber of mounting means for electrochemical cell 490 and 590, howevermore than three mounting means may be used if desired and/or necessary.Since each mounting means is individually adjustable, the provision ofthree mounting means permits the electrochemical cell 490 and 590 to beused on non-planar surfaces. In addition, even though electrochemicalcells 490 and 590 have been illustrated as being used to makemeasurements on generally horizontal surfaces, they could obviously beused to make electrochemical measurements on vertical substrates aswell.

FIG. 21 illustrates another embodiment of the electrochemical cell ofthe invention similar to that shown in FIG. 7. FIG. 21 shows anembodiment wherein the attachment means for biasing the cell towards asubstrate is modified to permit attaching the cell to substrates withwidely varying surface morphology, e.g. substrates which are not planaror have an irregular surface. The elements of FIG. 21 that are similarto those in FIG. 7 have similar numbering.

FIG. 21 shows a modification of the electrochemical cell shown in FIG.7. The electrochemical cell 270′ of FIG. 21 comprises a cylinder 272′which is closed at the top end by plate 273′ and has a necked-downportion 286′ closing its bottom end. Plate 273′ and necked-down portion286′ may be removably secured to the cylinder 272′ or they mayoptionally be integral with cylinder 272′. Necked-down portion 286′ hasan electrolyte opening 280′ therein. This electrolyte opening 280′ isprovided with a sealing means 282′ surrounding electrolyte opening 280′at the exterior surface of necked-down portion 286′ to seal cell 270′ tothe surface of substrate 102′. Sealing means 282′ may take the form ofan O-ring, gasket or any other suitable means.

Ports 274′ and 276′ are provided for insertion of a reference electrode(not shown) and a counter electrode (not shown). These ports aredesigned such that the port with an electrode inserted therein would beliquid tight. This could be accomplished, for example, by the use of aplug which held the electrode therein. The plug could be secured andsealed within port 274′ and/or 276′ using an O-ring, gasket, screwthreads or any other suitable means.

Plate 273′ has a filling/drain port 308′ incorporated therein to permitthe cell 270′ to be filled with electrolyte. This filling/drain meansincorporates a valve 310′ to open and/or close port 308′. This willpermit the cell 270′ to be conveniently emptied of electrolyte when thedesired measurements have been taken.

Necked-down portion 286′ is provided with a valve 284′ near electrolyteopening 280′. This permits the electrolyte opening 280′ to be opened orclosed. Valve 284′ may be a rotary valve, a slide valve or any othersuitable type of valve.

At least one mounting means is provided to removably andnondestructively secure cell 270′ to a surface of substrate 102′. Inthis figure two mounting means 315, 315′ are shown. Mounting means 315,315′ provide for adjustment of the cell 270′ towards and away fromsubstrate 102′. This allows for the electrolyte opening 280′ innecked-down portion 286′ to be biased against substrate 102′ and permitssealing means 282′ to seal cell 270′ against substrate 102′.

Mounting means 315 and 315′ have an attachment arm 300″, 300′ whichextends generally perpendicular to the longitudinal axis of cylinder272′ and which secures the mounting means to cylinder 272′. In additionmounting means 315, 315′ has legs 302, 302′ which extend generallyperpendicular to attachment arms 300″ and 300′″ respectively. One end oflocking universal joints 317 and 317′ are attached to legs 302 and 302′.The other end of locking universal joints 317 and 317′ is attached to afirst end of leg portions 325 and 325′ respectively. Securing means304″, 304′″ are attached to the other end of leg portions 325 and 325′.As shown, legs 302 and 302′ can move generally perpendicular to arms300″, 300′″. Locking universal joints 317 and 317′ permit leg portions325 and 325′ to be independently adjusted to allow securing means 304″and 304′″ to secure cell 270 to a substrate with irregular surfacemorphology. As shown, surface 102′ contains a substantial bend. Themodified attachment means of this embodiment permits the cell 270′ to besecurely mounted to this type of irregular surface. Securing means 304″,304′″ may comprise a suction cup, a magnet, releasable adhesive means orany other device capable of releasably and nondestructively securingcell 270′ to one surface of substrate 102′.

Certain applications may be such that only one mounting means 315 isnecessary, however two mounting means 315, 315′ are considered necessaryin most applications and three mounting means are considered the optimalnumber for general usage although more may be provided if desired ornecessary.

Any suitable type of joining member could be used to join legs 302 and302′ to leg portions 325 and 325′ instead of a locking universal joint.The main requirement would be the locking capability and the ability toangularly adjust the legs 302, 302′ and leg portions 325, 325′.

Operation:

In operation, substrate 102′ would be cleaned as necessary for thedesired measurements. This would involve cleaning in the area wheresecuring means 304″, 304′″ would contact the surface of substrate 102′.In addition, the area of substrate 102′ which would be directly underthe footprint of electrolyte opening 280′ would be cleaned and anycoating in this area may have to be removed in order to make the desiredelectrochemical measurements. Cell 270′ would be then be secured to thesurface of substrate 102′ using mounting means 315, 315′. Mounting means315, 315′ would be adjusted to compliment the morphology of surface102′. For example, in the situation shown in FIG. 21, the angularorientation of leg portion 325′ and leg 302′ would be adjusted to permitmounting means 304′″ to be securely attached to the left side ofsubstrate 102′ [as show] while mounting means 304″ is securely attachedto the right side of substrate 102′. Further adjustment of legs 302,302′ in relation to arms 300″ and 300′″ may be necessary in order toenable the cell 270′ to be securely mounted to substrate 102′.

Once cell 270′ has been securely mounted to substrate 102′, theremainder of the operation to take an electrochemical measurement withCell 270′ is the same as that described above for cell 270 of FIG. 7. Itshould be noted that cell 270′ is adapted to make electrochemicalmeasurements on horizontal surfaces, sloped surfaces, and even onsurfaces that are vertical.

FIGS. 22 and 23 show the fifth embodiment of the invention. Thestructure of electrochemical cell 700 permits accurate temperaturecontrol of the electrolyte and of the local substrate area where theelectrochemical measurements are being made. This cell also has anattachments means which permits the cell to be secured to substrateswith a somewhat irregular surface morphology. It is noted that cell 700is adapted to make electrochemical measurements on horizontal surfaces,sloped surfaces, vertical surfaces, and even on surfaces that areslightly beyond vertical.

FIG. 22 shows a plan view of cell 700 and FIG. 23 shows a side view ofcell 700. These two figures will be described together as they aredifferent views of the same cell with some common components hidden inone view but visible in the other.

Cell 700 comprises a base 726 which is shown with the shape of anirregular hexagon. Obviously, other shapes could be used. Base cover 732is mounted to the upper portion of base 726. Also mounted to base 726are leg base mounts 712, 712′ and 712″. These leg base mounts providethe mounting means for the suction cup assemblies 701, 701′ and 701″.

Each suction cup assembly comprises a large bellows-type pneumaticsuction cup 703, 703′ and 703″ with a coaxial venturi 702, 702′ and 702″mounted to the upper portion thereof. Venturi mount assemblies 708, 708′and 708″ attach coaxial venturis 702, 702′ and 702″ to adjustment screws704, 704′ and 704.″ Adjustment screws 704, 704′ and 704″ are carried inadjustment screw mounts 710, 710′ and 710″. Adjustment nuts 706, 706′and 706″ permit fine height adjustment of adjustment screws 704, 704′and 704″ with respect to the adjustment screw mounts 710, 710′ and 710″.

Adjustment screw mounts 710, 710′ and 710″ are attached to base 726 byleg base mounts 712, 712′ and 712″. The means attaching the adjustmentscrew mounts to the leg base mounts permits a coarse height adjustmentof adjustment screw mounts 710, 710′ and 710″ with respect to the legbase mounts 712, 712′ and 712″ as will be further described below.

Electronics component 734 is attached to base 726 between suction cupassemblies 701 and 701″. This electronics component comprises aminiature potentiostat similar to electronics component 50 shown anddescribed above with respect to FIGS. 12 and 14. Digital display 736 issimilar to digital display 54 described above and shown in FIG. 11.Electronics component 734 may also comprise temperature controlcircuitry whose function will be further discussed below. In addition,electronics control 734 may interact with one or more electro-mechanicalinterlock switches as described below.

Electrolyte tank 716 is mounted to cell 700 at a slight angle to thevertical to avoid problems with air bubbles in the electrolyte solutionin the electrochemical analytical chamber 724 which will be furtherdescribed below. The particular angle shown in FIGS. 22 and 23 is 10°from the vertical although other angles obviously may be suitable.Electrolyte tank 716 is connected to base cap 732 by quick-disconnectfittings 718 and 720 and positioned on base cap 732 by means of fluidtank base 714, 714′. Fluid tank base 714, 714′ is mounted on base cap732 and comprises a curved wing on each side which receives the outerportion of fluid tank 716.

As shown in FIG. 27, an electro-mechanical interlock switch 739 ismounted on shelf 714″ which connects wings 714, 714′. Electro-mechanicalinterlock switch 739 prevents operation of electrochemical cell 700 ifthe electrolyte tank 716 is not properly mounted to base 726 by means ofquick-disconnect fittings 718 and 720. The electro-mechanical interlockswitch may control circuitry in electronics component 734 to preventoperation of cell 700 when electrolyte tank 716 is not properlypositioned on the fluid tank base 714,714′. Electrolyte tank 716 isvented at the top portion thereof by vent means 738.

Reference electrode 729 is mounted on one side of base 726 and slightlyangled downwards from the horizontal. This is to avoid problems with airbubbles in the electrochemical analytical chamber 724 which will bediscussed further below.

An important feature of the invention is control of the temperature ofthe substrate surface where the electrochemical measurements are beingtaken. Another important feature of the invention is control of theelectrolyte solution temperature. It is well-known that the rate ofalmost every chemical reaction is dependent upon the temperature of thereactants. It is also true that the rate of electrochemical reactionsis, in like manner, dependent upon the temperature of the reactants. Ithas been discovered that, by eliminating the influence of temperature onthe reaction rate, more consistent and reliable results can be obtainedwhen making electrochemical measurements with the electrochemical cellsdisclosed herein.

With this in mind, the electrochemical cell of the invention has a meansto control the temperature of the substrate of interest in the areawhere the electrochemical measurements are being made and a means tocontrol the temperature of the electrolyte solution. It is noted thatthe embodiments disclosed herein all use heating means to control thetemperature of the local substrate area and the electrolyte; however, itis recognized that some situations might call for a cooling means tocontrol these temperatures.

The temperature control features of the instant invention involve theuse of heating elements in thermal contact with the substrate ofinterest near the area where the electrochemical measurements are beingmade and with the electrolyte solution. Each of these temperaturecontrol features will be further discussed below.

While some previous embodiments have been designed such that all powernecessary for operation of the cell is provided by an on-board battery,this embodiment requires substantially greater amounts of power for thetemperature control mechanisms. To this end, it is envisaged thatexternal power will be supplied via connector 740 [shown in FIG. 22]when cell 700 is in operation. In addition, this embodiment requirescompressed air to power the coaxial venturi assemblies 702, 702′ and702″ in order to provide a vacuum in suction cup assemblies 701, 701′and 701″.

The temperature control means for the substrate of interest is heatingpad 730. Heating pad 730 is a large annular heater which is mounted tothe lower surface of base 726 by annular heater pad mount 728. Heatingpad 730 and heater pad mount 728 surround analytical chamber 724.Heating pad 730 has a resistive temperature device [RTD] 733 or anothersuitable temperature measurement device embedded therein or attachedthereto to shut down operation of heating pad 730 when a predeterminedmaximum temperature is exceeded. Hex adjustment screws 722 and 722′permit the heater pad mount 728 and thus heating pad 730 to be movedtowards or away from base 726. Analytical chamber 724 has a gasket 736mounted to the lower end thereof which gasket serves to seal theanalytical chamber to the substrate of interest when electrochemicalmeasurements are being made. Analytical chamber 724 is shown in FIG. 23as extending slightly below the lower surface of heating pad 730.However, in normal operation of cell 700 this would not be the case asheating pad 730 would have been lowered to contact the surface of thesubstrate of interest prior to taking any electrochemical measurements.Analytical chamber 724 will be further described below.

FIG. 24 shows a bottom view of test fluid housing 750. FIG. 25 shows across-section view of test fluid housing 750 along section A-A of FIG.24. These two figures will be described together as they are differentviews of the same elements with some common components hidden in oneview but visible in the other. It is noted that test fluid housing 750is primarily contained within base 726 with portions thereof extendinginto base cap 732 and below base 726.

Test fluid housing 750 comprises three cylindrical portions, 751, 752and 754 made of a polymeric material. Test fluid housing portion 752 hasthe smallest portion 751 mounted to its upper surface. Portion 754 isintermediate in size between portions 751 and 752 and is mounted to thelower surface of test fluid housing portion 752. Quick-disconnectfitting 720 is mounted to test fluid housing portion 751. Electrolytefluid feed bore 778 starts in portion 751 and extends through portion752 to analytical chamber 724 which is contained within test fluidhousing portion 754 as shown in FIG. 25. A reference electrode bore 776for mounting reference electrode 729 [shown in FIG. 23] extends from anouter surface of portion 752 to intersect electrolyte fluid feed bore778. A vent pipe 772 extends from the upper surface of portion 752 tointersect electrolyte fluid feed bore 778 at the lower portion thereofas shown in FIG. 25. Vent pipe 772 has a valve 774 in the upper portionthereof to allow gas to escape from the analytical chamber 724, from thereference electrode bore 776 and from the electrolyte fluid feed bore778. During operation of cell 700, vent pipe 772 prevents gas bubbles inthe electrolyte fluid from interfering with accurate electrochemicalmeasurements. This feature is important because cell 700 can be used tomake electrochemical measurements on substrates with many differentorientations from generally horizontal to vertical and even to somewhatpast vertical.

Analytical chamber 724 as noted above is mounted within test fluidhousing portion 754. Chamber 724 comprises a passive metallic cylinder766 which is surrounded by a heating coil 768 and has a gasket 736extending from the lower portion thereof. Heating coil 768 has aresistive temperature device [RTD] 769 or another suitable temperaturemeasurement device embedded therein or attached thereto to shut downoperation of heating coil 768 when a predetermined maximum temperatureis exceeded.

The passive metallic cylinder 766 serves as a counter electrode whenmaking electrochemical measurements with cell 700.

The purpose of gasket 736 is to seal analytical chamber 724 to thesubstrate of interest. Stainless steel is an example of a passive metalwhich is very suitable for the cylinder 766 although other passivemetals may be used which would be suitable chambers for the specifictypes of electrochemical measurements desired. O-ring 770 is placedaround the upper portion of cylinder 766 to seal analytical chamber 724and to prevent electrolyte contact with heating coil 768. Bore 762 isprovided in test fluid lousing portion 752 to permit resistive thermaldevice [RTD] 764 or another suitable temperature-measuring device toaccess the electrolyte within analytical chamber 724. The RTD 764 [orother suitable temperature measurement device] permits the electronicscomponent 734 to control the electrolyte fluid temperature bycontrolling the operation of heating coil 768.

Bore 756 extends through test fluid housing portions 752 and 754 topermit an electro-mechanical interlock device 758 to access thesubstrate of interest when cell is in operation. Spring loaded contact760 is contained within the bottom portion of electro-mechanicalinterlock device 758. In operation, the electro-mechanical interlockdevice 758 may control circuitry in electronics component 734 to preventoperation of cell 700 when spring loaded contact 760 is not depressed bythe substrate as it would be when cell 700 is properly mounted on thesubstrate of interest.

Bores 780 and 784 [shown in FIG. 24] also extend through test fluidhousing portions 752 and 754. Bore 780 permits working electrode probe782 to make electrical contact with the working electrode which is thesubstrate of interest upon which the electrochemical measurements arebeing made. Bore 784 permits RTD 786 [or another suitable temperaturemeasurement device] to measure the temperature of the working electrode[the substrate of interest]. This connection permits electronicscomponent 734 to control the temperature of the substrate within themeasurement area by controlling the operation of heating pad 730 [shownin FIG. 23].

FIG. 26 shows the means which attaches adjustment screw mount 710 to legbase mount 712 and provides a coarse height adjustment as discussedabove. Obviously, similar means are provided to attach adjustment screwmounts 710′ and 710″ to leg base mounts 712′ and 712″. In FIG. 26adjustment screw mount 710 is shown with five linearly spaced holes 740,740′, 740″, 740′″ and 740″″ bored into the right side of adjustmentscrew mount 710. Each hole 740, 740′, 740″, 740′″ and 740″″ has asmaller perpendicular hole bored there through to permit a push pin [notshown] to be inserted into the holes.

Leg base mount 712 has a corresponding set of linearly spaced holes [notshown] bored therein. Pins 742, 742′ are removably secured in two of thecorresponding holes in leg base mount 712. Pins 742 and 742′ havetransverse bores 744 and 744′ there through. In operation, leg basemount 712 would be assembled to adjustment screw mount 710 with pins742, 742′ being inserted into corresponding holes 740 and 740″ inadjustment screw mount 710. When assembled, the perpendicular holes inadjustment screw mount 710 align with the transverse bores 744, 744′ ofpins 742, 742′. Push pins [not shown] are inserted through the alignedperpendicular holes and transverse bores 744, 744′ to secure theassembly. In order to adjust the relative vertical position ofadjustment screw mount 710 and leg base mount 712, the push pins wouldbe removed, adjustment screw mount 710 and leg base mount 712 would beseparated, and pins 742 and 742′ could then be inserted into differentholes, for example 740′ and 740′″. This would give a different relativeposition between adjustment screw mount 710 and leg base mount 712. Inaddition, pins 742, 742′ could be removed from their holes in leg basemount 712 and placed in other holes achieve different relativepositioning of adjustment screw mount 710 and leg base mount 712.

Operation:

Once the substrate surface is suitably prepared, cell 700 is positionedsuch that the analytical chamber 724 is over the substrate area ofinterest and the suction cup assemblies 701, 701′ and 701″ arepositioned on the substrate surface.

Compressed air from a suitable source [not shown] is provided to each ofthe coaxial venturi assemblies 702, 702′ and 702″ allowing the suctioncup assemblies 701, 701′ and 701″ to secure cell 700 to the substratesurface. The construction of suction cups 703, 703′ and 703″ and theindependent height adjustment at each suction cup permit the cell to besecured to a substrate surface that is moderately irregular, e.g. notplanar or a moderately rough surface.

The distance between analytical chamber 724 and the substrate surface isadjusted to the optimal distance for a good seal between the analyticalchamber 724 and the substrate surface using the coarse heightadjustments means illustrated in FIG. 26 and/or using the fine heightadjustment provided by adjustment nuts 706, 706′ and 706″. The heaterpad 730 will then be adjusted, as necessary, via hex adjustment screws722 and 722′. Heater pad 730 should then be in close contact with thesubstrate surface. It is noted that heater pad 730 is somewhat flexibleto allow for a suitable thermal connection to moderately irregularsurfaces. Electrical connections [using a cable, not illustrated] aremade between the reference electrode 729 and the electronics component734. Electrical power from an external source is provided to cell 700via connector 740.

A full electrolyte tank 716 is connected to cell 700 viaquick-disconnect fittings 718 and 720. Wings 714, 714′ guide electrolytetank 716 into place and the bottom end of electrolyte tank 716 contactselectro-mechanical interlock switch 739 when the tank is fully seated.Power is applied to the heating pad 730 and heating coil 768, asnecessary, to assure that the electrolyte fluid and the substratesurface area of interest achieve the optimum temperature. Once theoptimum temperatures are achieved, electronics component 734 will makeand store the desired electrochemical measurements.

FIG. 28 shows the sixth embodiment of the invention. Cell 799 similar tothe construction of cell 700 shown in FIGS. 22 and 23 but without theelectronics component 734 of cell 700. Cell 799 is designed to beconnected to an external potentiostat [not shown] and external circuitrywhich would control the analytical chamber heating elements and theheating pad.

The structure of electrochemical cell 799 also permits accuratetemperature control of the electrolyte and of the local substrate areawhere the electrochemical measurements are being made. This cell alsohas an attachments means which permits the cell to be secured tosubstrates with a somewhat irregular surface morphology. It is notedthat cell 799 is adapted to make electrochemical measurements onhorizontal surfaces, sloped surfaces, vertical surfaces, and even onsurfaces that are slightly beyond vertical.

Cell 799 comprises a base 826 which is shown with the shape of anirregular hexagon. Obviously, other shapes could be used. Base cover 832is mounted to the upper portion of base 826. Also mounted to base 826are leg base mounts 812, 812′ and 812″. These leg base mounts providethe mounting means for the suction cup assemblies 801, 801′ and 801″.

Each suction cup assembly comprises a large bellows-type pneumaticsuction cup 800, 800′ and 800″ with a coaxial venturi 802, 802′ and 802″mounted to the upper portion thereof. Coaxial venturis 802, 802′ and802″ are mounted to the upper portion of suction cups 800, 800′ and800″. Venturi mount assemblies which are not shown in FIG. 28 but whichare similar to venturi mount assemblies 708, 708′ and 708″ of FIG. 23attach to adjustment screws which also are not shown in FIG. 28 butwhich are similar to adjustment screws 704, 704′ and 704″ shown in FIG.23. These adjustment screws are carried in adjustment screw mounts 810,810′ and 810″. Adjustment nuts 806, 806′ and 806″ permit fine heightadjustment of the adjustment screws with respect to the adjustment screwmounts 810, 810′ and 810″.

Adjustment screw mounts 810, 810′ and 810″ are attached to base 826 byleg base mounts 812, 812′ and 812″. The means attaching the adjustmentscrew mounts to the leg base mounts permits a coarse height adjustmentof adjustment screw mounts 810, 810′ and 810″ with respect to the legbase mounts 812, 812′ and 812″ in the same manner as shown in FIG. 26.

Electrolyte tank 816 is mounted to cell 799 at a slight angle to thevertical to avoid problems with air bubbles in the electrolyte solutionas discussed above with respect to FIGS. 22 and 23. Electrolyte tank 816is connected to base cap 832 by quick-disconnect fittings not shown inFIG. 28 but which are similar to quick disconnect fittings 718 and 720shown in FIG. 23. Electrolyte tank 816 is positioned on base cap 832 bymeans of fluid tank base 814, 814′. Fluid tank base 814, 814′ is mountedon base cap 832 and comprises a curved wing on each side which receivesthe outer portion of fluid tank 816.

An electro-mechanical interlock switch is mounted on a shelf portion offluid tank base 814,814′. Neither the interlock switch or shelf portionis shown in FIG. 28 but they are identical to the showing in FIG. 27. Asshown in FIG. 27, an electro-mechanical interlock switch 739 is mountedon shelf 714″ which connects wings 714, 714′. Electro-mechanicalinterlock switch 739 prevents operation of electrochemical cell 700 ifthe electrolyte tank 716 is not properly mounted to base 726 by means ofquick-disconnect fittings 718 and 720. The interlock switch of cell 799operates in the same manner as that shown in FIG. 27. Thiselectro-mechanical interlock switch controls circuitry in an externalelectronics package [not shown] to prevent operation of cell 799 whenelectrolyte tank 816 is not properly positioned on the fluid tank base814,814′. Electrolyte tank 816 is vented at the top portion thereof byvent means 836.

Reference electrode 829 is mounted on one side of base 826 and slightlyangled downwards from the horizontal. This is to avoid problems with airbubbles as discussed above in regard to FIGS. 22 and 23.

An important feature of the invention is control of the temperature ofthe substrate surface where the electrochemical measurements are beingtaken. Another important feature of the invention is control of theelectrolyte solution temperature. It is well-known that the rate ofalmost every chemical reaction is dependent upon the temperature of thereactants. It is also true that the rate of electrochemical reactionsis, in like manner, dependent upon the temperature of the reactants. Ithas been discovered that, by eliminating the influence of temperature onthe reaction rate, more consistent and reliable results can be obtainedwhen making electrochemical measurements with the electrochemical cellsdisclosed herein.

With this in mind, the electrochemical cell of the invention has a meansto control the temperature of the substrate of interest in the areawhere the electrochemical measurements are being made and a means tocontrol the temperature of the electrolyte solution. It is noted thatthe embodiments disclosed herein all use heating means to control thetemperature of the local substrate area and the electrolyte; however, itis recognized that some situations might call for a cooling means tocontrol these temperatures.

The temperature control features of the instant invention involve theuse of heating elements in thermal contact with the substrate ofinterest near the area where the electrochemical measurements are beingmade and with the electrolyte solution. Each of these temperaturecontrol features will be further discussed below.

The temperature control means for cell 799 is identical to thetemperature control means for cell 700 except that it is achieved withexternal control circuitry [not shown] instead of an onboard electronicscomponent. Thus the temperature of the substrate of interest iscontrolled by a heating pad identical to heating pad 730 shown in FIG.23. The heating pad is a large annular heater which is mounted to thelower surface of base 826 by annular heater pad mount not shown in FIG.28 but identical to heater pad mount 728 shown in FIG. 23. The heatingpad and heater pad mount surround the analytical chamber and have hexadjustment screws 822 and 822′ permit the heater pad mount and thusheating pad to be moved towards or away from base 826 as described andshown above with respect to FIG. 23 and cell 700.

Reference electrode 829 is mounted to base 826 in the same manner asreference electrode 729 is mounted to base 726 for cell 700 describedabove and shown in FIG. 23.

Since cell 799 does not have an on-board electronics component, plugs834, 836 and 840 provide electrical connection between the electrodes,the temperature control devices and interlocks and the heating elementsof cell 799 and the external control means. They also provide for asource of external power for the heating pad and the heating coil.

Operation:

Once the substrate surface is suitably prepared, cell 799 is positionedsuch that the analytical chamber is over the substrate area of interestand the suction cup assemblies 801, 801′ and 801″ are positioned on thesubstrate surface.

Compressed air from a suitable source [not shown] is provided to each ofthe coaxial venturi assemblies 802, 802′ and 802″ allowing the suctioncup assemblies 801, 801′ and 801″ to secure cell 799 to the substratesurface. The construction of suction cups 800, 800′ and 800″ and theindependent height adjustment at each suction cup permit the cell to besecured to a substrate surface that is moderately irregular, e.g. notplanar or a moderately rough surface.

The distance between the analytical chamber and the substrate surface isadjusted to the optimal distance for a good seal between the analyticalchamber and the substrate surface using the coarse height adjustmentsmeans illustrated in FIG. 26 and/or using the fine height adjustmentprovided by adjustment nuts 806, 806′ and 806″. The heater pad will thenbe adjusted, as necessary, via hex adjustment screws 822 and 822′. Theheater pad should then be in close contact with the substrate surface.It is noted that the heater pad is somewhat flexible to allow for asuitable thermal connection to moderately irregular surfaces. Electricalconnections [using cables, not illustrated] are made between thereference electrode 829, connectors 834, 836 and 840 and the externalelectronics [not shown]. The external electronics would comprise acontrol system and a potentiostat. Electrical power from an externalsource is provided to cell 799 via connector 840.

A full electrolyte tank 816 is connected to cell 799. Wings 814, 814′guide electrolyte tank 816 into place and the bottom end of electrolytetank 816 contacts an electro-mechanical interlock switch [not shown]when the tank is fully seated. Power is applied to the heating pad andheating coil, as necessary, to assure that the electrolyte fluid and thesubstrate surface area of interest achieve the optimum temperature. Oncethe optimum temperatures are achieved, the external electronics willmake and store the desired electrochemical measurements

1. A compact and portable electrochemical cell for makingelectrochemical measurements on the surface of a substrate of indefinitesize comprising: a. an analytical chamber with a top and a bottom end;b. sealing means associated with the bottom end of said chamber to sealsaid bottom end to one surface of a substrate of indefinite size; c.means to mount a counter electrode in said analytical chamber; d. meansto mount a reference electrode in said analytical chamber; e. securingmeans to removably and nondestructively secure said bottom end of saidanalytical chamber against one surface of a substrate of indefinitesize, said securing means further comprising adjustment means to adjustthe distance between said analytical chamber and one surface of asubstrate of indefinite size in order to bias said analytical chambertowards the surface of a substrate of indefinite size.
 2. The compactand portable electrochemical cell of claim 1 wherein said securing meansfurther comprises one or more suction cups.
 3. The compact and portableelectrochemical cell of claim 1 further comprising a first plate closingsaid bottom end of said analytical chamber, said first plate having anopening therein and with said sealing means surrounding said opening toseal said analytical chamber to one surface of a substrate of indefinitesize.
 4. The compact and portable electrochemical cell of claim 3wherein said first plate is integral with said bottom end of saidanalytical chamber.
 5. The compact and portable electrochemical cell ofclaim 3 further comprising a second plate closing said top end of saidanalytical chamber.
 6. The compact and portable electrochemical cell ofclaim 5 further comprising: a. a filling means attached to saidanalytical chamber; b. a venting means attached to said analyticalchamber; c. said filling means permitting introduction of an electrolyteto the interior of said analytical chamber; d. said venting meanspermitting the venting of gases contained in said analytical chamberwhen an electrolyte is introduced therein; and, e. wherein said secondplate is integral with said top end of said analytical chamber.
 7. Thecompact and portable electrochemical cell of claim 6 wherein: a. saidfilling means comprises a valve penetrating said second plate; and b.said venting means comprises an air-liquid separator.
 8. The compact andportable electrochemical cell of claim 7 wherein said analytical chamberis provided with drain means permitting the draining of electrolyte fromsaid analytical chamber.
 9. The compact and portable electrochemicalcell of claim 8 further comprising: an electronics component mounted onsaid analytical chamber; said electronics component comprising; a. meansto apply a potential between a reference electrode and a substrate, b.means to apply a current between a counter electrode and a substrate, c.an electrometer capable of measuring the potential between a substrateand a reference electrode as a function of time or as a function ofapplied current, d. said electrometer also being capable of measuring acurrent between a counter electrode and a substrate as a function oftime or as a function of applied potential, and e. means to output themeasurements collected.
 10. The compact and portable electrochemicalcell of claim 1 wherein: a. the top end of said analytical chamber isclosed by a plate; b. the bottom end of said analytical chamber furthercomprises a necked-down section with a reduced size opening at the lowerend of said necked-down section; c. said sealing means surrounds saidopening to seal said analytical chamber to one surface of a substrate ofindefinite size;
 11. The compact and portable electrochemical cell ofclaim 10 wherein: a. said plate is integral with the top end of saidanalytical chamber; b. said analytical chamber is further provided withfilling means and venting means, said filling means permittingintroduction of an electrolyte to the interior of said analyticalchamber, and said venting means permitting the venting of gasescontained in said analytical chamber when an electrolyte is introducedtherein.
 12. The compact and portable electrochemical chamber of claim11 wherein said necked-down section further comprises a valve meansadjacent said opening with said valve means permitting said necked-downsection to be either open or closed.
 13. The compact and portableelectrochemical cell of claim 12 further comprising: a. an electronicscomponent mounted on said analytical chamber; b. said electronicscomponent comprising; means to apply a potential between a referenceelectrode and a substrate, means to apply a current between a counterelectrode and a substrate, an electrometer capable of measuring thepotential between a substrate and a reference electrode as a function oftime or as a function of applied current, said electrometer also beingcapable of measuring a current between a counter electrode and asubstrate as a function of time or as a function of applied potential,and means to output the measurements collected.
 14. The compact andportable electrochemical cell of claim 10 wherein: a. said plate isattached to the top end of said analytical chamber; b. said analyticalchamber is further provided with filling means and venting means, saidfilling means permitting introduction of an electrolyte to the interiorof said analytical chamber, and said venting means permitting theventing of gases contained in said analytical chamber when anelectrolyte is introduced therein.
 15. The compact and portableelectrochemical cell of claim 14 wherein said necked-down sectionfurther comprises a valve means adjacent said opening with said valvemeans permitting said necked-down section to be either open or closed.16. The compact and portable electrochemical cell of claim 15 whereinsaid adjustment means further comprises: a. at least two attachment armsmounted generally perpendicular to the analytical chamber outer surfaceon opposing sides thereof; b. a leg mounted generally perpendicular toeach said attachment arm, with said leg comprising first and secondsegments; c. means permitting the first segment of each said leg to bemoved in a first direction perpendicular to said attachment arm; d. saidmeans also permitting said first segment to be moved in a seconddirection perpendicular to said attachment arm and in opposition to saidfirst direction; and e. joining means joining said first and second legsegments, said means comprising a locking universal joint to permit theangle between said first and second leg segments to be widely varied,and to lock said segments in position when said angle has been set. 17.The compact and portable electrochemical cell of claim 16 wherein saidsecuring means further comprises suction cups mounted to said second legsegments at the end thereof opposite to said joining means.
 18. Thecompact and portable electrochemical cell of claim 15 furthercomprising: a. an electronics component mounted on said analyticalchamber; b. said electronics component comprising; means to apply apotential between a reference electrode and a substrate, means to applya current between a counter electrode and a substrate, an electrometercapable of measuring the potential between a substrate and a referenceelectrode as a function of time or as a function of applied current,said electrometer also being capable of measuring a current between acounter electrode and a substrate as a function of time or as a functionof applied potential, and means to output the measurements collected.19. A compact and portable electrochemical cell for makingelectrochemical measurements on the surface of a substrate of indefinitesize comprising: a. an analytical chamber comprising a counter electrodeand having a top and a bottom end; b. sealing means associated with thebottom end of said chamber to seal said bottom end to one surface of asubstrate of indefinite size; c. a base plate, with said analyticalchamber being mounted within said base plate; d. means to mount areference electrode in said base plate and near said analytical chamber;e. an electrolyte fluid tank mounted to said base plate and in fluidiccontact with said analytical chamber and said reference electrode; f.securing means mounted to said base plate to removably andnondestructively secure said bottom end of said analytical chamberagainst one surface of a substrate of indefinite size, said securingmeans further comprising adjustment means to adjust the distance betweensaid analytical chamber and one surface of a substrate of indefinitesize in order to bias said analytical chamber towards the surface of asubstrate of indefinite size; g. said adjustment means furthercomprising at least two leg base mounts mounted generally perpendicularto said base plate on opposing sides thereof; h. mounting means mountinga suction cup assembly on each said leg base mount; and, i. saidmounting means comprising a screw with an associated adjustment nutattached to said leg base mount; wherein said screw and said adjustmentnut permit said suction cup assembly to be moved towards or away from asubstrate of indefinite size.
 20. The compact and portableelectrochemical cell of claim 19 wherein said suction cup assemblycomprises a bellows-type pneumatic suction cup.
 21. The compact andportable electrochemical cell of claim 20 wherein said electrolyte fluidtank is mounted to said base plate at a slight angle to the vertical.22. The compact and portable electrochemical cell of claim 21 whereinsaid slight angle is approximately 10 degrees.
 23. The compact andportable electrochemical cell of claim 19 further comprising a first gasventing means in fluidic contact with said top end of said analyticalchamber.
 24. The compact and portable electrochemical cell of claim 19further comprising a second gas venting means mounted on saidelectrolyte fluid tank.
 25. A compact and portable electrochemical cellfor making electrochemical measurements on the surface of a substrate ofindefinite size comprising: a. an analytical chamber comprising acounter electrode and having a top and a bottom end; b. sealing meansassociated with the bottom end of said chamber to seal said bottom endto one surface of a substrate of indefinite size; c. a first temperaturecontrol means mounted to the outside surface of said analytical chamber;d. a base plate, with said analytical chamber being mounted within saidbase plate; e. a second temperature control means mounted beneath saidbase plate and surrounding said bottom end of said analytical chamber;f. means to mount a reference electrode in said base plate and near saidanalytical chamber; g. an electrolyte fluid tank mounted to said baseplate and in fluidic contact with said analytical chamber and saidreference electrode; and h. securing means mounted to said base plate toremovably and nondestructively secure said bottom end of said analyticalchamber against one surface of a substrate of indefinite size, saidsecuring means further comprising adjustment means to adjust thedistance between said analytical chamber and one surface of a substrateof indefinite size in order to bias said analytical chamber towards thesurface of a substrate of indefinite size.
 26. The compact and portableelectrochemical cell of claim 25 wherein said electrolyte fluid tank ismounted to said base plate at a slight angle to the vertical.
 27. Thecompact and portable electrochemical cell of claim 26 wherein said angleis approximately 10 degrees.
 28. The compact and portableelectrochemical cell of claim 25 further comprising a first gas ventingmeans in fluidic contact with said top end of said analytical chamber.29. The compact and portable electrochemical cell of claim 25 furthercomprising a second gas venting means mounted on said electrolyte fluidtank.